Billboard number-one singles chart (which preceded the Billboard Hot 100 chart), which was updated weekly by the Billboard magazine, was the main singles chart of the American music industry since 1940 and until the Billboard Hot 100 chart was established in 1958.

This article relies largely or entirely on a single source. (April 2020)

Before the Billboard Hot 100 chart was established in August 1958, which was based on a formula combining sales data of commercially available singles and airplay on American radio stations, the Billboard used to publish several song popularity charts weekly. Throughout most of the 1940s the magazine published the following three charts:

• Best Selling Singles – ranked the biggest selling singles in retail stores, as reported by merchants surveyed throughout the country.
• Most Played Juke Box Records (debuted January 1944) – ranked the most played songs in jukeboxes across the United States.
• Most Played by Jockeys (debuted February 1945) – ranked the most played songs on United States radio stations, as reported by radio disc jockeys and radio stations.

The list below includes the Best Selling Singles chart only.

Key

 ♪   – Number-one single of the year

• List of Billboard number-one singles
• 1940s in music