Catlett was born in San Francisco, California. He spread out a career out for himself playing excitable, offcious blowhards, but some other actors may have done it better. As a San Francisco citizen, he started out in vaudeville with a detour for a while in opera before breaking it out into films in the mid-1920s.

Catlett also provided the voice of Foulfellow the Fox in the 1940 Disney animated film Pinocchio.

Walter made a handful of silent film appearances, but didn't catch on until the advent of talking pictures allowed movie-goers to go and see his full comic repertoire. Two of his most-remembered roles were as the stage manager given to distraction by James Cagney in Yankee Doodle Dandy in 1942 and the local constable who throws the entire cast in jail, and winds of there himself, in the Howard Hawks classic screwball comedy Bringing Up Baby in 1938.

Catlett appeared as hotel resort tycoon 'Timber Applegate' in the musical film Lady, Let's Dance (1944) which starred ice skating sensation 'Belita' and James Ellison.

Before his death, he began role-playing in such 1950s films like Davy Crockett and the River Pirates in 1956, Friendly Persuasion also in 1956, and Beau James in 1957.

Walter Catlett died in 1960 in Woodland Hills, California while suffering from a stroke.