Schwartz was born in Budapest, Hungary. His family moved to New York City when he was 13 years old. He took various music related jobs including demonstrating and selling sheet music in department stores before being hired full time by the Shapiro-Bernstein Publishing House of Tin Pan Alley as a staff pianist and song-plugger. He published his first composition (a Cakewalk) in 1899. He known as an accomplished lyricist, although also continued writing music.
In 1901 he started working with William Jerome. They collaborated on many songs which were used in Broadway shows, as well as the Zigfield Follies. Their biggest hit together was the 1910 song "Chinatown, My Chinatown", still popular with Dixieland bands. Schwartz and Jerome stopped working together in 1913.
Schwartz continued working on show tunes through 1937.
Jean Schwartz died in Los Angeles, California.