Phillip Glasser as Fievel Mousekewitz. While "Fievel" is the generally accepted spelling of his name, the opening credits spell it as "Feivel", the more common transliteration of the Yiddish name (פֿײַװל Fayvl). (Cf. Shraga Feivel Mendlowitz and Feivel Gruberger.) (The ending credits spell his name as "Fievel".) However, many English-speaking writers have come to adopt the spelling Fievel (with reversed i and first e) especially for this character; it was this spelling that was used on the film's poster, in promotional materials and tie-in merchandise, and in the title of the sequel An American Tail 2: Fievel Goes West. His last name is a play on the Jewish-Russian last name "Moskowitz", the name of the human occupants of the house his family is living under in the beginning of the film.
Amy Green as Tanya Mousekewitz (singing voice provided by Betsy Cathcart), Fievel's older sister. Optimistic, cheerful, and obedient, she continued to believe that he was alive after he was washed overboard en route to America. She was given an American name "Tillie" at the immigration point at Castle Garden.
John P. Finnegan as Warren T. Rat, a cat disguised as a rat and the leader of the Mott Street Maulers, a gang of cats who terrorize the mice of New York City. He is accompanied nearly all the time by his accountant Digit, a small British-accented cockroach.
Nehemiah Persoff as Papa Mousekewitz, the head of the Mousekewitz family who plays the violin and tells stories to his children.
Erica Yohn as Mama Mousekewitz, Fievel's mother. Countering Papa's dreamy idealism, she is a level-headed pragmatist, and appears to be the stricter of the couple. She also has a fear of flying.
Pat Musick as Tony Toponi, a streetwise young mouse of Italian descent and with a "tough New Yorker" attitude. The name "Toponi" is a play on "topo", the Italian word for "mouse".
Dom DeLuise as Tiger, a very large, cowardly, long-haired, orange tabby cat who also happens to be vegetarian (with the exception of the occasional fish).
Christopher Plummer as Henri, a pigeon of French descent, who is in New York City while building the Statue of Liberty.
Cathianne Blore as Bridget, an attractive mouse with an Irish accent and Tony's girlfriend. Kind, passionate, yet soft-spoken, she acts as a kindly motherly figure to Fievel.
Neil Ross as Honest John, a local Irish-born mouse politician who knows every voting mouse in New York City. An ambulance-chasing drunkard who takes advantage of voters' concerns to increase his political prestige, he is a caricature of the 19th-century Tammany Hall politicians.
Madeline Kahn as Gussie Mausheimer, a German-born mouse considered to be the richest in New York City, who rallies the mice into fighting back against the cats.
Will Ryan as Digit, Warren's British cockroach accountant who has a fondness for counting money, but is plagued by frequent electrical charges in his antennae whenever he gets nervous or excited.
Hal Smith as Moe, a fat rat who runs the sweatshop Fievel is sold to by Warren.
Dan Kuenster as Jake, first burly Member of the Mott Street Maulers. Enjoys listening to his boss' music on the violin as he, Tiger, and the other gang members play poker. He later catches Fievel after the very first chase. He guards the poor imprisoned Fievel until Tiger wakes him up and comes to take his place. They later chase him again after Tiger has freed him. But they never catch him again. They chase him all the way to the Chelsea Piers They are later chased away by the "Giant Mouse of Minsk".