The son of a whiskey peddler, Walter Woolf King began singing for his supper at quite a young age, in churches especially. Following graduation, he pursued his dream and partnered in a vaudeville musical act with pianist Charles Le Maire . He made his Broadway debut in 1919 and developed a resilient name for himself during the 1920s as a baritone in various operettas and musical comedies. Billed as Walter Woolf and Walter King in his early career, he finally settled on all three names by the mid-1930s. He eventually was drawn to early talking films and began promisingly enough as a dapper lead in plush musicals, but was quickly relegated to swank villainy in Marx Brothers and Laurel and Hardy slapstick. He also found steady offers on radio but, tired of his stalled career, became an actor's agent. Walter would return from time to time in gruff bit roles as a (now) bulkier, grey-haired corporate or aristocrat, particularly on TV.

Retired from full-time acting to become an agent but left the profession after ten years when he developed an ulcer.Once sued Warner Brothers for breach of contract after dismissing King following his very first picture which failed at the box office. The Studio claimed his singing voice was unsuitable for sound. An out-of-court settlement was reached in his favor.