This article contains the list of characters featured in the Tom and Jerry animated series, given in the order of the era in which they first appeared.

Main Tom and Jerry

Thomas "Tom" (originally called "Jasper") is a bluish grey and white domestic shorthair cat. He is usually, but not always, portrayed as living a comfortable and pampered life, while Gerald "Jerry" (originally called "Jinx"), a brown house mouse, always lives in close proximity to Tom. Despite being very energetic, determined, and much larger, Tom is no match for Jerry's wits. Jerry also possesses surprising strength for his size, sometimes even greater than Tom's, being able to lift items such as anvils with relative ease, and withstand big impacts. Although cats usually chase mice to eat them, it is quite rare for Tom to actually try to eat Jerry. Instead, he tends to compete with Jerry to taunt him (even as revenge) or to obtain a reward from a human (including his owner(s) or master(s)) for catching him or for generally doing his job as a house cat well. By the final "fade-out" of each cartoon, Jerry usually gets the best of Tom.

However, on rare occasions Tom triumphs over Jerry. This usually happens when the latter pushes Tom a little too far, such as in The Million Dollar Cat, where Jerry learns that Tom will lose his newly acquired wealth if he harms any animal, "including mice." He then torments Tom a touch too much until he retaliates. In Timid Tabby, Tom's look-alike cousin pushes Jerry over the edge. Occasionally and ironically, there are times when they both lose, like when Jerry's final trap or attack on Tom backfires or he overlooks something, like in Filet Meow, where Jerry orders a shark from the pet store to scare Tom away from eating a goldfish, but finds himself entirely intimidated as well. They even occasionally end up as friends, although within this set of stories, the truce is often ruined by some last minute event. One story that has a friendly ending is Snowbody Loves Me.

Both characters display sadistic tendencies, usually taking pleasure in tormenting each other, although it is often in response to a triggering event. However, when one character appears to be in mortal danger from an unplanned situation, or due to actions by a third party, the other will develop a conscience and save him. Occasionally, the duo bonds over a mutual sentiment toward an unpleasant experience and ultimately, attacking each other is more of a game than serious. Multiple shorts show the two getting along with minimal difficulty and they are more than capable of teamwork when the situation calls for it, usually against a third party who manages to torture and humiliate them both. These partnerships are usually forgotten when an unexpected event happens, or when one character feels that the other is no longer necessary. This is the case in Posse Cat, when they agree that Jerry will allow himself to be caught if Tom agrees to share his reward dinner, but Tom then reneges. Other times, Tom does keep his promise to Jerry and the partnerships do not so quickly dissolve after a solution to the problem is found.

Hanna-Barbera era (1940–1958, 2000–2005) The following characters were introduced in the theatrical shorts that were directed by William Hanna and Joseph Barbera.

Spike and Tyke

Spike, occasionally referred to as Butch or Killer, is a stern though occasionally dim-witted grey bulldog who is particularly disapproving of cats, but is gentle towards mice (though in his debut appearance, Dog Trouble (1942), Spike goes after both Tom and Jerry), and later, his son Tyke. In the shorts, Jerry would often try to get Tom in trouble with Spike so that the bulldog would beat him. Spike has a few weaknesses that Tom tries to capitalize upon: his possessiveness about his bone and his ticklishness. His first speaking role was in The Bodyguard (1944), where he was voiced by Billy Bletcher up until 1949, from which point he was voiced by other actors, including Patrick McGeehan, Jerry Mann, Bob Shamrock, John Brown, Fred Karbo, Stan Freberg, and Daws Butler. Spike is very protective towards his son and gets very angry at Tom if Tyke is bothered or harmed. After Daws Butler, Maurice LaMarche, Frank Welker, John DiMaggio, Michael Donovan, Phil LaMarr, Rick Zieff, and Bobby Cannavale would all perform Spike's voice. Unlike his father Spike, Tyke does not speak in Tom and Jerry or the 2014 TV series (aside from laughing in one short); he does speak in Tom and Jerry Kids, voiced by Patric Zimmerman.

Nibbles

Nibbles (also known as Tuffy) is a little, blue/gray, diaper-wearing orphan mouse who is close to Jerry and appears frequently with him, especially in the comics. His cartoon debut came in the short The Milky Waif (1946). Nibbles was later featured in the Academy Award-winning short The Little Orphan (1949).

He is sometimes seen as Jerry's nephew, but occasionally referred to as an orphan. Although these details are very inconclusive. Nibbles is often shown eating excessively as he is always hungry. In his first animated appearance, Tuffy was left on Jerry's doorstep, abandoned by his parents. Tom enjoys chasing Nibbles/Tuffy as much as he does Jerry.

Though the character was created as Tuffy for the comics in 1942, his early animated appearances from 1945 used the name Nibbles. During the 1950s and subsequently, the mouse was called Tuffy on-screen as well. In Tom and Jerry: The Magic Ring (2002), the name Nibbles was used again; and he was depicted as a pet-store mouse whom Jerry doesn't know.

In the Mouseketeer shorts, Nibbles speaks in French and English. He also is not Jerry's nephew; rather, he is the son of François Mouse—who does not make an appearance, but his name was given in two letters in the short Touché, Pussy Cat! (1954).

Like his guardian Jerry, Nibbles is often mistaken for a girl due to his extraordinarily high pitched voice. He was voiced by Francoise Brun-Cottan in the Mouseketeer shorts, Lucille Bliss in Robin Hoodwinked, Lou Scheimer and Frank Welker in The Tom and Jerry Comedy Show, Charlie Adler in Tom & Jerry Kids, Tara Strong in Tom and Jerry: The Magic Ring, Reece Thompson in Tom and Jerry Tales (season 1), Chantal Strand in Tom and Jerry: A Nutcracker Tale and Tom and Jerry Tales (season 2), Kath Soucie from 2010 onwards, and Alan Marriott in the video games Fists of Furry (2000) and War of the Whiskers (2002).

Butch

Butch is a black alley cat who made his first appearance in the Tom and Jerry series in the short Baby Puss (1943), alongside Topsy and the already-established Meathead. His character, however (along with the character of Toodles Galore), first appeared in the MGM short (and Butch's only solo cartoon) The Alley Cat (1941), directed by Hugh Harman. Though unnamed in the short, he was referred to as "Tom" in a model sheet. Butch is the leader of the alley cat bullies who are usually friends with Tom and help him catch Jerry. In his first appearance, Baby Puss, Butch was an antagonist, tormenting Tom after Tom's young girl owner treated him like a baby—to the point of dressing Tom up in a diaper, a bonnet, and pink paw mittens. Thus costumed, Tom couldn't help, but be a figure of fun—both for Butch and his gang, and for Jerry. Butch also battles with Tom over Toodles Galore and her affections, creating a love triangle between him and Tom in a couple of shorts including the shorts, Springtime for Thomas (1946) and Casanova Cat (1951). In some cartoons, such as A Mouse in the House (1947), Butch battles with Tom to catch Jerry. Butch is usually portrayed as a homeless alley/street cat although in the short, Blue Cat Blues (1956), Butch is apparently a millionaire who wins the attention of Tom's love interest due to his immense wealth much to Tom's dismay. Butch also appears in a cartoon in the short-lived Spike and Tyke cartoon series, Scat Cats (1957), as a house cat owned by George and Joan, who in later installments of the original series own Tom. Butch briefly appears in Heavenly Puss (1949) as one of the cats trying to enter heaven, apparently having been killed in a fight with a dog (wearing bandages and with a full set of dog teeth clamped onto his tail).

He is voiced by Harry E. Lang in The Alley Cat, Jack Mather in Baby Puss, Frank Graham in Springtime for Thomas and Trap Happy (1946), Raul Martinez in Springtime for Thomas (singing voice), Jerry Mann in Casanova Cat, Fred Karbo in Life with Tom, Daws Butler in Baby Butch (1954), Smarty Cat (1955) and Scat Cats (1957), Alan Marriott in Tom and Jerry in Fists of Furry (video game, 2000), Marc Silk in Tom and Jerry in War of the Whiskers (video game, 2002), Maurice LaMarche in Tom and Jerry: The Magic Ring (2002), Tony Cervone in The Karate Guard (2005), Colin Murdock in Tom and Jerry Tales (2006–08), Joey D'Auria in The Tom and Jerry Show (2014–2021) and Tom and Jerry in New York (2021), and Nicky Jam in Tom & Jerry (2021).Nicky Jam reveló qué personaje interpretará en Tom y Jerry, la película (in Spanish)

Toodles Galore Toodles Galore is an attractive white female cat, who usually wears a large blue bow around her neck, and is supposedly Tom's love interest, although Tom is a reputed playboy, and had other love interests before and after Toodles. Toodles is the only love interest who appeared more than twice. During the classic era, Tom had to compete twice against Butch and even once against Spike for Toodles's affection, and he lost them all. In Casanova Cat (1951), Toodles even fell in love once with Jerry.

Toodles is one of the more anthropomorphic animals in the early series, but her depiction varies by period. She never speaks and she rarely moves around. She has a feline main body, not a human one; however, details like whiskers come and go. She also has cat ears and nose. However, she has many human attributes. She sits in very human poses and walks on two feet (as does Tom in all but the very early shorts, where he chases Jerry on all fours). She has human-shaped hands with painted nails, and rather human eyes and lips made up as a human woman of the era might. In most appearances, like the other cats, she wears nothing but her fur, but she wears a bathing-suit in Salt Water Tabby (1947) with a human feminine figure.

Toodles appears in four episodes of Tom and Jerry Tales (2006–2008): "Joy Riding Jokers," "Spaced Out Cat," "Piranha Be Loved By You," "Abracadumb," and "Flamenco Fiasco," credited in the latter episode as "Senorita Cat" and voiced by Chantal Strand. In the later series, The Tom and Jerry Show (2014–2021), she makes cameo appearances in the episodes "Belly Achin'", "Cat Napped", "Don't Cut the Cheese", and "A Star Forlorn". She would later make a full appearance in the Season 4 episode "Tap Cat". She also appears in Tom and Jerry in New York, voiced by Rachael MacFarlane. A white cat similar in appearance to her appears in the 2021 film.

Mammy Two Shoes