Walter Henry Passmore (10 May 1867 – 29 August 1946) was an English singer and actor best known as the first successor to George Grossmith in the comic baritone roles in Gilbert and Sullivan operas with the D'Oyly Carte Opera Company.

Passmore began performing professionally at the age of fourteen in the pantomime Cinderella. He was apprenticed to a piano maker and then worked as a pianist before returning to acting, making his London debut in 1890. In 1893 he joined the D'Oyly Carte Opera Company, soon becoming the company's principal comedian. He created roles in the original productions of the last two Gilbert and Sullivan operas and in many other Savoy Operas. He played the patter roles in several Gilbert and Sullivan revivals, and he toured for the company.

In 1903 Passmore left the company and began a career in musical comedies, plays and pantomimes in the West End and on tour that lasted for thirty years. His West End appearances included roles in such productions as The Earl and the Girl (1903), The Talk of the Town (1905). He often appeared on stage with his second wife, Agnes Fraser.