Born Roy B. Weissburg in Russia, West adopted his professional name some time after emigrating to America. He appeared in many short films, first in Apartment No. 13 in 1912. In 1917 movie theaters couldn't get enough Charlie Chaplin comedies, and an enterprising producer hired West, who had been doing comic pantomimes on the vaudeville stage, to make imitation-Chaplin subjects to meet the demand. West, wearing the identical "tramp" costume and makeup, copied Chaplin's movements and gestures so accurately that he is often mistaken for the genuine performer. Chaplin himself saw the Billy West company filming on a Hollywood street, and told West, "You're a damned good imitator." Some West comedies were later re-released on the home-movie market as "Charlie Chaplin" pictures. Most of the West comedies of 1917–18 resembled the Chaplin comedies of 1916–17, with Oliver Hardy approximating the villainy of Eric Campbell, and Leatrice Joy in the Edna Purviance ingenue role.
In 1922 West became his own producer, and dropped the Chaplin imitation in favor of a dapper, straw-hatted, pencil-mustached character. Moving behind the cameras in 1925, West produced a brief series of slapstick comedies co-starring the fat-and-skinny team of Oliver "Babe" Hardy and Bobby Ray, and a series of "Winnie Winkle" comedies with Ethelyn Gibson.
West took small roles in sound films, first for small independent companies and later for Columbia Pictures.