This is a list of characters in The Replacements.
- Todd Daring (voiced by Nancy Cartwright) - He is the lazy, trouble-making, and selfish one of the siblings, and he usually uses the Fleemco phone to replace people for selfish purposes. He hates school, learning, and reading. His catch phrases include "don't judge me" and "what the butterscotch?" First appeared: "Todd Strikes Out". Last appeared: "Irreplaceable".
- Riley Eugene Daring (voiced by Grey Griffin) - She is the kinder, more caring and reliable sibling who enjoys school. She generally uses the Fleemco phone to replace mean or unfair adults. She is a girly girl and enjoys playing baseball, playing the violin, horses, ponies, Hornet Hive Scouts, candy, and pretty much any form of sugar. At one point she was part of the Journalism staff at school. She has a crush on Johnny Hitswell and they became a couple in the second season. In "Heartbreak in the City", Johnny broke up with her because of her controlling attitude. She claims she is over him, despite many people who claim otherwise. Riley also has a mission: Get Todd to do the right thing and be selfless. First appeared: "Todd Strikes Out". Last appeared: "Irreplaceable".
- Richard "Dick" Marion Daring (voiced by Daran Norris) - He is the siblings' world-famous daredevil adoptive father. He is a semi-former stunt artist, and is constantly working on new tricks. His appearance resembles that of Evel Knievel. He is also rather immature, and is seen having a teddy bear known as "Evel Bearnievel". He thinks that C.A.R. is his best friend, though C.A.R. doesn't see it that way. Like Todd, Dick isn't smart at all, but he is a better cook than K. First appeared: "Todd Strikes Out". Last appeared: "Irreplaceable".
- Agent K Daring (voiced by Kath Soucie) - She is the siblings' adoptive mother who is of British descent and is a super spy. From an outside view it may seem she doesn't care for her kids or husband, but in fact she loves them devotedly, even though she may express it through a recording or videotape. If something is done unfairly, she fixes it very quickly. She is seen to be a terrible cook. Her career as a spy has also made her highly suspicious of anything that is the least bit out-of-place, to the point of paranoia. In the episode Abra K Dabra!, it is revealed that she has stage fright and that her middle name is Mildred. She also has a habit for thinking all her chores are secret missions. She plays classical violin. K once took karate lessons from the evil Master Pho to bust his secret evil bank-robbing karate gang. Even though she's just as logical as C.A.R., she seems to favor Dick over him. Even though both Dick and Agent K are the replacement adoptive parents, they still seem to be very much in love and care for Riley and Todd as their own children. First appeared: "Todd Strikes Out". Last appeared: "Irreplaceable".
- C.A.R.T.E.R. (voiced by David McCallum) - C.A.R.T.E.R., aka C.A.R., is the high-tech family car with a British accent. He can do just about anything, but is not always willing to do something for the family, especially not for Dick. He often calls Dick a twit, but is often indifferent to him. He does not wish to let Dick drive him, presumably under the assumption that Dick's daredevil habits would wreck him. He prefers to use a maneuver called "The Oslo Option" to scare Dick, which consists of C.A.R.T.E.R. pulling out a large spinning buzzsaw blade from his hood. The family usually refers to him as simply C.A.R. which is most likely a parody of K.I.T.T from Knight Rider. In the episode Tasumi Unmasked, it is revealed that C.A.R. used to be a one-man band player back when he wanted to join other one-man band members, but was kicked out for not being perfect. They destroyed his instruments. First appeared: "Todd Strikes Out". Last appeared: "Irreplaceable".
- Prince Cinnamon Boots - The Daring family's pet mule. He was originally given to Riley by her father when she asked for a show horse. P.C.B. has many talents but is often forgotten by his family after Dick says "I keep thinking we're forgetting something." First appeared: "Skate-Gate". Last appeared: "Irreplaceable".
- Conrad Fleem (voiced by Jeff Bennett) - Conrad is the mysterious owner of the Fleemco company. He processes Todd and Riley's requests whenever they call him. He has a very long mustache. At the end of the series it is revealed that Conrad is Riley and Todd's long lost uncle, and his face is shown for the first time. First appeared: "Todd Strikes Out". Last appeared: "Irreplaceable".
Associated with Todd
- Jacobo Jacobo (HA-CO-BO) (voiced by Candi Milo) - Todd's best friend who is of Mexican descent. He has a funny looking mouth. Jacobo loves mystery books and has a secret talent for singing. He is always trying to win the affections of Agent K, even in the episode, "Irreplaceable," when he started to date Tasumi. First appeared: "Todd Strikes Out". Last appeared: "Irreplaceable".
- Shelton Gunnar Klutzberry (voiced by Jeff Bennett) - Shelton is the stereotypical nerd at school. He always seems to be wherever Todd and Riley are, and he just wants to be part of their friend group. He is Jewish, and he celebrates his bar mitzvah in one episode. First appeared: "Todd Strikes Out". Last appeared: "Irreplaceable".
- Buzz Winters (voiced by Grey Griffin) - Buzz is a wanna-be bully and is Todd's arch nemesis. He usually makes corny jokes then laughs at them saying "Good one Buzz!" and "I got to start writing these down!". Although he is normally a bully, in some episodes they have put their differences aside and even become friends. Like Todd, Buzz hates school, and he has a habit of cheating. He has many secrets including his love of the theater, and what he calls his only two shames, his small feet, and ice skating. First appeared: "Todd Strikes Out". Last appeared: "Irreplaceable".
- Donny Rottweiler (voiced by Jess Harnell) - Donny is a professional bully who is much taller than Todd, but still attends his school. He is Buzz's mentor and Todd's other nemesis, he is feared because of his giant size. First appeared: "The Insecurity Guard". Last appeared: "R2: A Tale of Two Rileys". He was also mentioned in "Irreplaceable" by Shelton.
Associated with Riley
- Tasumi (voiced by Lauren Tom) - She is Riley's best friend, who is of Japanese descent. She wears pink battle armor, and she claims that her family is part of a crime-fighting team. In the episode "Tasumi Unmasked", it is revealed that Tasumi is in fact a Japanese pop star on the run from the paparazzi. After this episode, she takes her armor off for good. First appeared: "Todd Strikes Out". Last appeared: "Irreplaceable".
- Abbey Wilson (voiced by Erica Hubbard in Season One, Tempestt Bledsoe in Season Two) - She is Riley's other best friend. Even though she hates the popular girls such as Sierra, she is seen wanting to be a part of them so bad, and has a habit of telling Sierra she is cool, even though she doesn't mean to. It also seems that her parents are rich. She sometimes can be hypocritical. She has a little sister named Tiffany who dated Todd in the episode "A Little Tiff". First appeared: "Todd Strikes Out". Last appeared: "A Tale of Two Rileys".
- Johnny Hitswell (voiced by Dee Bradley Baker) - He is the subject of Riley's affection and her middle school sweet heart. Even though every girl in the school is all over him, he tends to pay no attention to them most of the time, except for his annual Kumquat Day card readings. He enjoys basketball and baseball, and plays on the same baseball team as Todd and Riley. It is true that he likes Riley, because he asked her out on a date and then kissed her. In season two, he starts dating Riley as boyfriend and girlfriend. In "Heartbreak in the City", Johnny breaks up with Riley for being to controlling after she followed him all the way to New York City. He once said in a later episode that she could be smothering as she was in a conversation with her friends. By the end of the series, he actually admits that he wants to get back together with Riley, but he says this while talking to her robot duplicate, and it is never shown if he and Riley do get back together. First appeared: "Todd Strikes Out". Last appeared: "R2: A Tale of Two Rileys".
- Sierra McCool (voiced by Tara Strong) - She is the popular girl at school, the head cheerleader, and Riley's arch nemesis. She constantly competes with Riley for the affections of Johnny Hitswell. She has her own posse (Jennifer and Claudia) and a huge, conceited ego. "Cheer Pressure" reveals that she is a fan of a sci-fi show called Star Journeys, leading to a short-lived bond with Todd. First appeared: "The Jerky Girls". Last appeared: "Todd Busters". She was mentioned in "Irreplaceable".
- Jennifer and Claudia - Two blonde twin girls who are normally seen with Sierra McCool. In the episode, "The Insecurity Guard" from the first season, a common gag was for the two girls to be commenting on what they are wearing when Todd falls in a mud puddle next to them, ruining their clothes. First appeared: "The Jerky Girls". Last appeared: "R2: A Tale of Two Rileys"
Minor and recurring characters
- Principal Cutler (voiced by Jeff Bennett) - He is the Inuit principal of George Stapler Middle School. Since he is from Alaska, he allows school on major snow days until Todd and Riley changed it one time. He is also very cheap and cares about money over the students, the school, and the faculty (he saves money for a vacation on Tahiti). First appeared: "Skate-Gate". Last appeared: "R2: A Tale of Two Rileys".
- Shelly Klutzberry - Shelton's older sister who has less appearances than her brother. She resembles her brother but doesn't change appearance when her glasses are taken off. In "Late Night With Todd and Riley" she is first mentioned as Shelton's sister and also we learn she loves Dustin Dreamlake. Though never mentioned, she presumably already had her bat mitzvah. First appeared: "Best Friends For-Never?". Last appeared: "R2: A Tale of Two Rileys".
- Phil Mygrave (voiced by Bruce Campbell) - Dick's stunt coordinator and brother. He is not very good with measurements, as he doesn't use proper units of measurements, rather just "tweaking the thingy on the whatchimacallit a smidge". He has also been married six times, and has poor advice for maintaining a relationship. He was twice replaced by Riley. First when Riley felt that his setting up of Dick's stunts were unprofessional and dangerous, and nearly ruins Dick's career by making all his stunts too safe, and second when Riley tried to get Dick a better love coach, and almost ended up costing Dick his stunt secrets. His name is a play on the phrase "fill my grave", referring to his shoddy assembly of Dick's stunts, a fact only noticed by C.A.R.T.E.R. He also appears briefly in "You Got Schooled" and "Double Trouble".
- Agent B (voiced by Carolyn Seymour) - Agent K's mother and Todd and Riley's grandmother. She is the headmistress of the Royal Academy of Spies. She seems not get along with K before the episode "London Calling", but in the episode they reconcile and B became a loving grandmother with Riley and Todd. She and her husband also appeared in "Dick Daring's All-Star Holiday Stunt Special".
- Agent G (voiced by Michael York) - Agent K's father and Todd and Riley's grandfather. He is the chief inventor of the Royal Academy of Spies, and gave cool presents to Todd and Riley in the episode "London Calling". He scared Dick when he saw the five clones of Agent G, claiming that no one would like 5 fathers-in-law.
- Gordo Glideright (voiced by Jeff Bennett) - Dick's stunt rival. He is always trying to steal Dick's stunt secrets. He once had Phil Mygrave as his stunt coordinator, and injured himself. He also tried to steal Dick's stunt secrets during his time as Dick's love coach. First appeared: "Jumping Mad". Last appeared: "Irreplaceable".
- Dustin Dreamlake (voiced by Jason Marsden) - A parody of Justin Timberlake. Riley's idol. He danced at Riley's 13th birthday party/Also on the Christmas Special Episode. First appeared: "The Insecurity Guard". Last appeared: "A Tale of Two Rileys".
- Ace Palmero (voiced by Dee Bradley Baker) - Local news reporter of Pleasant Hills, he always refers to himself as "I, Ace Palmero". A recurring gag involves only his profile being shown on TV with the camera changing whenever he turns to face it. First appeared: "Skate Gate". Last appeared: "Truth or Daring".
- Dr. Hans Herkmer - A scientist who works for the space program. He worked with Dick Daring in becoming a Space pilot in "Space Family Daring". He also was his replacement stunt coordinator in "Jumping Mad", and almost ruined his career as a stuntman by making all of Dick's stunts too safe, and replacing him with a monkey. First appeared: "Jumping Mad". Last appeared: "Irreplaceable".
- Amanda McMurphy (voiced by Candi Milo) - A hard-hitting investigator reporter who helped Riley with the school newspaper. She also got the story on how Todd's rat was able to reverse the aging process. She eventually found out about Riley and Todd's Fleemco phones and asked them to replace her because she was tired of working for the George Stapler Middle School. First appeared: "The Truth Hurts". Last appeared: "Irreplaceable".
- Fabian Le'Tool (voiced by Rob Paulsen) - A professional hairdresser who gives Riley a full makeover for a dance. He also prepares Todd's hair for a press conference about Todd's reversing the aging process. There's usually a running gag that exposes the fact he wears a wig (even by himself).
- Davey Hunkerhoff (voiced by Zac Efron) - A lifeguard (and a young parody of David Hasselhoff) that Riley used to make Johnny Hitswell jealous in the episode "Davey Hunkerhoff" when he refused to notice her. However, he actually had feelings for Riley, which inevitably led to complications between the two.
- Skye Blossoms (voiced by Tara Strong) - A common replacement. A hippie who does not judge people and believes the answers to all of your questions are "what you feel the answer is." First appeared: "Cheer Pressure". Last appeared: "Crushing Riley".
- Mr. Vanderbosh (voiced by Rob Paulsen) - Riley's stern teacher who sent Riley to double detention after she accidentally ripped his pants, and later gave her a quadruple detention. He also sent Riley and Tasumi to the guidance office in "Best Friends For-Never?". He's usually mean at times. First appeared: "Quiet Riot!". Last appeared: "Toddbusters".
- The Kelpmans (voiced by Chip Chinery and Mary Elizabeth McGlynn) - Next door neighbors to the Darings. They were once replaced on Halloween by the Zupecks. It turned out that they worked on developing ice creams which made them too busy to prepare any Halloween decorations.
- Prime Minister Ricobo Pricobi and Veronica Mudslinger - Two replacements Todd and Riley hired as campaign managers in the episode "Running from Office". Todd got Prime Minister Pricobi, the self-elected leader of his own country, where he had to deal with "rebel monkeys"; meanwhile, Riley got Veronica Mudslinger, a well-researched political speaker who spoke out against the prime minister. On election day, Todd and Riley had already settled their dispute, and they told their campaign managers they're quitting. The two managers marched on stage, arguing that it was the others' fault. But as they went on, they immediately became attracted to each other, and they started kissing in front of the audience, traumatizing them.
- Lady Lady (voiced by Grey Griffin) - A professional wrestler who settled Tasumi and Riley's feud for Todd in "Best Friends For-Never?". She encouraged Riley and Tasumi to settle their problems in the ring, and she trained both girls for a wrestling match in the school gymnasium. Riley and Tasumi eventually settled their differences without hitting each other, but then Abbey stepped into the ring and fought them both, which delighted Lady Lady. In “Serf’s Up”, Lady Lady starred in Wrestleocity XXXVII on pay-per-view. In the storyline, she is about to get married to the Canadian Canucklehead, but then Abraslam Lincoln, her ex-boyfriend, crashed her wedding. Also appeared as one of Dr. Scorpius' minions in "Irreplaceable".
- Wrestler Announcer (voiced by Jim Cummings) - He announces the wrestling matches since Riley and Tasumi's end-of-friendship argument in "Best Friends For-Never?". He announced Lady Lady's marriage to Canadian Canucklehead in "Serf's Up."
- Celebrity Starr (voiced by Miley Cyrus in the first appearance, Jessica DiCicco in the second appearance) - This celebrity was first found replacing Shelton's imaginary girlfriend, Zelda because Shelton had defended Riley when Sierra put a love note in Riley's locker saying it was from Shelton. Riley felt bad and had Zelda replaced with Celebrity who liked nearsighted nerds. She became so annoying that Shelton broke up with her. Even with that she vowed to never let him go causing him to lose his glasses making him a "complete hottie", which wasn't her taste and she broke up with him. In contrary to all that there was gossip going around that Shelton broke up with her, which he did. She returned to get revenge on the young nerd by making a movie to dehumanize him. She ended up casting Todd in hopes to woo him. In the end, Todd turned her plan around and protected his friend. She instead made a movie to make fun of Todd. Also appeared as one of Scorpius' minions in "Irreplaceable".
- Zephremiah and Silent Joe (voiced by Dee Bradley Baker) - a pair of twins that are friends of Todd's. They were both in Todd's boy choir. Zephremiah apparently likes sports. His twin brother, Silent Joe, is apparently sensitive and rarely talks and communicates by grunting. Joe only talks in "Boyzroq!" when he and his brother are arguing about which one is the sensitive one.
- Splatter Train - A fictitious character in a recurring horror movie throughout the show. One of these times is when Todd has a sleepover and shows a scary movie with this character in it, (I think I can, I think I can, splatter you!), and another is in Riley's flashback where she was on a date with Johnny Hitswell at the movies.
- Tiny Evil (voiced by Jason Marsden) - An enemy of Agent K. He is first mentioned in "Riley's Birthday" when Agent K convinced Dustin Dreamlake to sing at her party by telling him that she needed his help capturing "the cleverly disguised spy known as Tiny Evil". Is not actually seen until a much later episode, "Canadian Fakin'", where he pretended to be a boy from Canada in order to infiltrate Agent K's secret room of weapons and use them against her, on Dr. Scorpius' orders.
- Dr. Scorpius (voiced by Rob Paulsen) - Archenemy of Agent K and the main antagonist of the series. He has a scorpion tail-shaped beard and is usually seen trying to take over the world in some way. He's also known for speaking with a lisp. In "The Spy That Wasn't Riley", he tried to destroy Antarctica with a giant laser cannon. In another episode, he was seen relaxing on a beach that Todd and Riley happened to be on at the time. In "The Rizzle", Todd finds out that he needs glasses, but Agent K thinks he has been infected with "Dr. Scorpius' Genetically Crafted Island Eye-Fog". Appeared in "The Spy That Wasn't Riley", "Canadian Fakin'", "Glee by the Sea", and "Irreplaceable". Mentioned in "CindeRiley", "German Squirmin'", "The Rizzle", and "Private Todd".
- Goober and T-Bone (voiced by Dee Bradley Baker and Jess Harnell) - Radio DJs who are idolized by Todd. Throughout the show, they will make random appearances where they host radio contests, etc. Usually these contests will involve the Party Peacock in some way. They were replaced by Buzz Winters in the episode "Phone-less In Pleasant Hills" when he found Riley's FleemTel phone.
- Buck Spikes (voiced by John Dimaggio)- a tough baseball coach who replaced Todd and Riley's old coach, Pops. Spike keeps pushing kids to the limit, and when they strike out, he cruelly throws them into a cage. Spikes does not appear until the series finale, "Irreplaceable," as one of Dr. Scorpius's minions.
- Puterdude13 (voiced by Jeff Bennett) - A "cool and mysterious recluse" (he's really a nerd) who runs the online interactive game, Fleemster. He was only seen in one episode where he met Todd and Riley after Todd got too obsessed with Fleemster.
- Heather Hartley - The "Her Girl" for Teen Swoon Magazine. She has an outrageous hairstyle and usually carries around her pet turtle on a leash. According to Tasumi, "she was on the cover because she was famous, but she was famous for being on the cover". Anyway, she was replaced by Riley after she finally got sick of everyone at her school emulating her, only to become the new Her Girl herself.
- Petrov (voiced by Dee Bradley Baker) - Another enemy of Agent K. Has appeared in a few episodes where he is usually opposed by Agent K and promptly apprehended by her.
- Dr. Clonemaster - Yet another Agent K rival. He was seen only in the episode, "The Means Justify the Trend", in a flashback of Agent K. The cause of this flashback was Riley attempting to confide in her mother about everyone in her school dressing just like Heather Hartley, (see above). After Riley told her about this, she fears that the evil Dr. Clonemaster is up to his old tricks again, and promptly leaves to fight him.
- Dingo McGee - The replacement sent by Fleemco when Todd got sick of an archaeologist treating them like babies on a field trip in the episode "Field Trippin'". He's an adventurous, usually reckless, explorer who plays the didgeridoo. He also returned in a later episode where he hosted the popular TV show, Volcano Island, in which the families of Buzz Winters, Shelton Klutzberry, and Todd and Riley Daring all competed. He descends from Australia.
- Robo Fleem SGX (voiced by Diedrich Bader) - A giant security robot that replaced the incompetent security guard at Todd's school in "The Insecurity Guard". However, the robot later went crazy and tried to destroy Riley when she tried to return it to Fleemco. This robot is the reason George Washington Middle School became George Stapler Middle School, because it threatened to destroy a teacher if she didn't say Todd was right the George Stapler was the first Presdident of the United States. Its head also makes cameo appearances in the School in the episodes "Ratted Out" and "She Works Hard for the Movies". Another one was manufactured by Dr. Scorpius in "Irreplaceable" to destroy Todd's friends.
- Mrs. Shusher (voiced by Tara Strong) - The shush-happy librarian at George Stapler Middle School. Todd got sick of her forcing everyone to be quiet, and later replaced her with a librarian who was the complete opposite of her. She returned later in the episode when her replacement was returned by Todd and Riley.
- Gammazor, Mecha-Gammazor, and Grammazor - All supposed enemies of Tasumi. There are pictures of them on her "list" whenever she brings it out and threatens to put Riley on it. They both possibly descend Godzilla, Mecha-Godzilla, and as a running gag, Grammazor which only appeared in the episode Tasumi Unmasked.
- Garth the Janitor- the school janitor that is constantly being replaced by Todd and (more often) Riley when they need a quick replacement. Garth is not very enthusiastic about his job and is extremely lazy. He is also not very bright but seems to know that whenever he inconveniences the Darings, he gets to go somewhere nice (usually). He is also the leader of the school Smite Club and was also one of Doctor Scorpius's minions in "Irreplaceable."
- Mrs. Fragile - a replacement who is very fragile. She becomes very upset when Buzz pronounces her name "fragile" instead of "Frah heel leh." She also becomes upset when she thinks Riley and Tasumi are acting dumb to take advantage of the substitute teacher.
- Bailey - a surfer who only appears in "Glee by the Sea". She helped Todd rebel against Gleeful Glenn's rules, and Todd fell in love with her. In addition to surfing, Bailey enjoys making fun of weird tourists and engaging in burping contests. She also liked hanging out with a jock named Procter, though she gradually got bored with Procter's vanity. After some convoluted attempts by Todd to win Bailey back, Procter challenged Todd to a surf-off where the winner gets to keep her. However, Bailey didn't appreciate being treated as a trophy, and she chose Todd even after Procter won the surf-off. She was last seen limbo dancing at the luau.
- Procter Skorpius - the son of Dr. Skorpius, Agent K's archenemy. He is rather vain; he brags about spending time at the gym, and he likes to flex his muscles. He enjoyed hanging out with Bailey. In an effort to get rid of Todd, Procter challenged him to a surf-off where the winner gets Bailey for himself; Procter planned to cheat by using a technologically advanced surfboard built by his father. However, after Procter won, Bailey told him that she's not a prize to be won, and she ended up with Todd. Procter was last seen with his parents at the luau. Like Bailey, Procter only appears in "Glee by the Sea".
- Kamil Settar - a new student in "Snide and Prejudice" who recently moved to Pleasant Hills from Bangladesh. After a bad first impression, Riley considers him her rival. In fact, Riley is unaware that Kamil likes her, and that he gets nervous around girls he likes. At the end of the episode, they admit that they like each other, and then they kiss. Kamil never appears again, and Riley goes back to liking Johnny.
- Terrence - a blind student who only appears in "Injustice is Blind". Terrence often brags about his heightened sense of smell. At first, he gets on Todd's good side by humiliating Buzz for his smelly armpits. Terrence does not take a liking to Todd's friends, and he later tries to bully Todd into becoming his personal servant. The students and faculty are led to believe that Todd is harassing Terrence because he is blind. After Terrence makes Jacobo into his servant, Todd decides to use Terrence's heightened sense of smell against him. Todd traps Terrence in a small room and farts, only stopping when Terrence agrees to make a videotaped confession.