Gus Arnheim (September 4, 1897 – January 19, 1955) was an influential American pianist and bandleader, renowned for his contributions to early jazz and dance music. Born in Philadelphia and raised in Chicago, Arnheim began his career as a pianist and accompanist to vaudevillian Sophie Tucker. In 1919, he formed a trio with Abe Lyman and Henry Halstead at the Sunset Inn in Santa Monica, California, which set the stage for his future success.

Arnheim joined Lyman's orchestra as a pianist before establishing his own band in 1927. His orchestra gained fame in the 1920s and 1930s, particularly during their legendary residency at the Cocoanut Grove nightclub in Los Angeles from 1928 to 1932. Arnheim's sophisticated arrangements and the orchestra's performances attracted a wide audience, including Hollywood celebrities.

He played a pivotal role in the career of Bing Crosby, with whom he recorded several songs that contributed to Crosby's rise as a solo artist. Arnheim's orchestra also featured notable musicians such as Fred MacMurray, Russ Columbo, and Stan Kenton. Arnheim's compositions included hits like "I Cried for You" and "Sweet and Lovely."

Throughout his career, Arnheim's orchestra was known for its blend of early jazz, hotel music, and ballroom dance, which captivated audiences across the nation. Gus Arnheim passed away in Los Angeles in 1955, leaving behind a legacy as one of the most popular bandleaders of the early 20th century.