This is a list of characters that appear in The Magic School Bus original series books (1986–2021), The Magic School Bus television series (1994–97) and The Magic School Bus Rides Again (2017–2020).

Main The school is known as Walkerville Elementary, named after the fictional town of Walkerville, where it is located. The classic series books --which were the books by Joanna Cole and Bruce Degen-- had a larger number of students in Ms. Frizzle's class (19 instead of 8). However, 11 of those characters were omitted in the TV series, the TV tie-in books (based with the TV series), and the video game series.

Frizzle sisters Valerie Felicity Frizzle Valerie Felicity Frizzle (voiced by Lily Tomlin in the TV series, Tina Marie Goff in the games, Judy Graubart in the Scholastic Audio Tapes, and Polly Adams in the Scholastic Audio CDS and digital audio books) is a third to fifth grade teacher of Walkerville Elementary. In the first series she is normally referred to as "Miss Frizzle" or "Ms. Frizzle", but her students often call her the "Friz". While she is eccentric and somewhat strange, the Friz is very intelligent, kind, resourceful, happy, funny, supportive, loving and somewhat motherly. She loves making jokes revolving around the lesson she teaches, even if she is the only one laughing. She makes flamboyant entrances to start the class, causing some to remark "How does she do that?" A redhead, she wears wacky dresses that reflect the subject of each adventure and earrings that glow before a field trip begins. She usually winks before the earrings glow (in the original books, her dress on the last page usually hinted at the plot of the next book; the very last book sees it covered with question marks) she enjoys singing, seems unafraid of danger, and often refers to her relatives or ancestors during trips. She can make a lot of jokes like Carlos, and she also admires Carlos's jokes. She appears to be very attached to the bus, almost as if having a nostalgic connection to it. She also loves to surprise the students and although she denies that she knows everything, she seems to never be in the dark side about her students' activities. To Arnold, she is strange, but he and his friends still love and respect her. Some of Ms. Frizzle's ongoing catchphrases are, "Bus, do your stuff!", "Take chances, make mistakes, get messy!", "Hit it Liz!", "As I always say...", "To the bus!" or "Wahoo!"

Valerie appears in The Magic School Bus Rides Again as "Professor Valerie Felicity Frizzle, Ph.D.", with Tomlin once again providing her voice. In this series, she answers phone calls in the call-in segments (replacing the producers scene in the original series) along with her pet monkey named Goldie, and usually gives some clue as to the topic of the next episode. Mostly, in the new series, she sometimes but not always shows up, and is always known for being shown at the ending.

Fiona Felicity Frizzle Fiona Felicity Frizzle (voiced by Kate McKinnon) is Valerie Frizzle's younger sister and the class's new teacher. She borrows a lot of her sister's catchphrases; such as "Bus, do your stuff!", among many others. Similar to her sister, Valerie; her skirt and necklace often change each episode based on the topic. Just like her sister, Fiona often quotes random relatives and friends of hers; but she does not share all the same catchphrases (and does not fully share personalities) with her sister.

Liz Liz (voiced by Catherine Thompson in the games) is the class pet Jackson's chameleon who goes on most of the field trips with Ms. Frizzle and the students, often getting herself into dangerous comedic situations. She appears to get a little jealous when the bus receives more attention than she does. In the episode "Gets Ants in its Pants", she is visibly annoyed and very disappointed when she does not get the recognition she deserves.

Liz is mute, but often does things that one would not expect from a chameleon in real life; such as driving the bus and her scales not changing color to match her surroundings. There are a few instances where she is heard making a sound. Two of these instances occurred during "Inside Ralphie". She yawned when Ms. Frizzle was on the phone with Ralphie's mother, and she sneezed when Ralphie saw the bus going through his nose. In "Wet All Over", she hyperventilated when trying to escape from the girls' bathroom. When she goes to Herp Haven for a brief period in "Cold Feet"; her packing list includes claw polish, scale moisturizer, and fang-paste. If Ms. Frizzle has to leave the students for a brief period for any reason or if the class must split up, she leaves Liz in charge, acting as a sort of substitute teacher. In "In a Pickle", she is the supposed "Judge" in Ms. Frizzle's trial for stealing Keesha's first prize cucumber/turning it into a pickle; she wears the wig, and the outfit, and carries the gavel.

While Liz is mute on the show, she speaks in the CD-ROMs (although it appears that only the player can hear her). She is also seen at the end of most episodes with the producers of the Magic School Bus.

Liz also appears in the disclaimers at the end of episodes in the TV show.

Students Narrator The Narrator (voiced by Alice Playten in the Scholastic Audio Tapes, Cassandra Lee Moriss in the Scholastic Audio CDs and Digital Audiobooks, and Tony Sperry in the TW Kids Audio Adaptations) is the main character in the original series books, the books adapting the TV episodes and the audio adaptations, narrating the events happening. Its currently unknown who they are or what their name is.

Note: In the Scholastic Audio Tapes, the kids are voiced by various kids from PS 41 and Saint Ann's School (Brooklyn) in New York City.

Arnold Perlstein Arnold Matthew Perlstein (voiced by Amos Crawley in Season 1, Danny Tamberelli in Seasons 2-4 in the original series, Miles Kolseci-Vieira and Roman Lutteroitti in The Magic School Bus Rides Again) is a bespectacled, Jewish-American boy. He is often seen as somewhat of a coward, but he is actually braver than he's given credit for (in "The Busasaurus", he scares off a T. Rex to save the class) Arnold also inspires the class with ideas and they call him a genius. In the episode "Shows and Tells", he mentions that his great-aunt is the famous archaeologist "Arizona Joan", a parody of Indiana Jones. He frequently bemoans a lot and shows concern about Ms. Frizzle's wild field trips, but on several occasions, he proves himself fiercely loyal to the teacher herself, as in "Lost in Space" where he defends her against his cousin Janet. Another example of this is in "In a Pickle" where he acts as a lawyer for Ms. Frizzle, taking his job almost too seriously. He has an intense interest in and knowledge of rocks and minerals and an extensive rock collection. Because of this, he is the only child to be a member of Granite, the Great Rock Admirers' National Institute of Tectonics Experts ("Goes Cellular") in "Cracks a Yolk", he and Dorothy Ann share the only kiss on the series when she kisses him on the cheek. It is implied in the episodes "For Lunch" and "Holiday Special", that he has a big crush on Wanda and vice versa, but in "Wet All Over", he has a crush on a girl in another class named Tiffany. It is also hinted in "The Busasaurus", that Phoebe has a big crush on him as well. In "Goes to Seed", he mentions he is allergic to pepper and pollen. In some episodes such as "In The City", he is known as the "Big Eater" of the show, because he's always hungry and likes food and eating all the time, just like Shaggy and Scooby-Doo. His middle name, Matthew, is mentioned in "Ms. Frizzle's Adventures: Medieval Castle". In most episodes, he usually says "I knew I should have stayed home today." or a variant of it. He has a very bossy, rude, know-it-all cousin, named Janet who often antagonizes Ms. Frizzle and the class; while Arnold often has trouble standing up to her demands, when things get very serious, he refuses to let Janet have her way. His favorite color is orange, revealed in "Makes a Rainbow" and "Goes Cecullar".

Carlos Ramón

Carlos Ramon (voiced by Daniel DeSanto in the original series and Leke Maceda-Rustecki in The Magic School Bus Rides Again) is the Colombian-American class clown, always making a pun or joke about whatever situation the class is in. He is a hands-on learner, preferring to invent unique devices, such as a best-loved stuffed animal, an instrument or rain catcher, rather than learn from a book like Dorothy Ann. Carlos tries to be quite funny by telling several jokes, but they often only backfire and cause the kids to groan "Carlos!" in an aggravated manner. By contrast, Ms. Frizzle seems to really enjoy his jokes, sometimes even complimenting him on being observant in the process of making them up. He is very kind and outgoing, but he can sometimes also have a very bossy side as well. Despite this, Carlos is extremely good-hearted and has a brotherly instinct about him. In "The Magic School Bus Going Batty", his father also makes puns, to which the other kids' parents would respond, "Mr. Ramon!" also in unison. In the episode called "Get Ready, Set, Dough", Carlos has the responsibility of making chocolate cake for Ms. Frizzle's birthday. In "Getting Energized", he entertains a crowd and can even do impressions of Arnold Schwarzenegger. In one of the producer segments, one of the kids points out that Carlos's bad puns must come from the producers as heard in one of the phone calls.

Dorothy Ann Hudson

Dorothy Ann Hudson (voiced by Tara Meyer in the original series and Gabby Clarke in The Magic School Bus Rides Again) is the class reader and bookworm, always looking for a fact in one of her many books and is considered the brain of the class. She is usually called "D.A." by the others. She always carries her pink satchel, which holds her books. In the episode "Blows Its Top", Dorothy Ann loses her books, but realizes she does not need them to learn about things. She appears to love astronomy, especially in "Out of This World" and "Sees Stars", where she is seen to have a telescope. In "Sees Stars", Dorothy Ann is celebrating her birthday, but she is sick and stays home that day, making her the second and last student after Ralphie to be sick in an episode. She appears to enjoy physics too, as she is seen with a physics book in "Plays Ball". In the beginning of "Out of this World", she has a terrible nightmare about an asteroid crashing into her school and in the climax, she is the captain of the ship and she has her own ideas to save our planet. Dorothy Ann's last name is never mentioned in the books or the original TV show; however, her last name is mentioned to be "Hudson" in the sequel series, The Magic School Bus Rides Again. Its also revealed that she has a younger sister, named Evan. She is one of three kids known to have siblings, the other two being Carlos and Wanda. When reading about different facts, D.A. usually begins by saying, "According to my research the" In the original series, she had a slight British accent and pronounced "research" with the accent on the second syllable. In The Magic School Bus Rides Again, she pronounces it with the accent on the first syllable, as it is usually pronounced in the United States. In The Magic School Bus Rides Again, her book satchel is replaced by a purple tablet computer.

Jyoti Kaur Jyoti Kaur (voiced by Birva Pandya) is an Indian-American girl who enrolls at Walker Elementary during the events of The Magic School Bus Rides Again. An expert on technology, she can create 3D holograms of herself, and she has even built a sentient robot named Naniben. Similar to Wanda, she opts to go where no one has ever gone before, and she is skilled in martial arts. For her catchphrase, she describes her feelings using gerunds.

Keesha Franklin