# List of Billboard number-one singles of 1940

In 1940, The Billboard began compiling and publishing the National Best Selling Retail Records chart. Debuting in the issue dated July 27, it marked the beginning of the magazine's nationwide tracking of record sales in the United States. Initially titled the "National List of Best Selling Retail Records", the weekly ten-position chart was tabulated using sales figures received from a selection of merchants across the country. Prior to its introduction, The Billboard had produced lists ranking music by various metrics such as performance in vaudeville venues, jukebox plays, sheet music sales, and regional airplay.
The first National Best Selling Retail Records number-one single was "I'll Never Smile Again" by Tommy Dorsey and His Orchestra. Featuring vocals by Frank Sinatra and the vocal group the Pied Pipers, the song topped the chart for twelve consecutive weeks and elevated Sinatra to national popularity.

## Chart history

| Issue date | Song | Artist(s) |
| July 27 | "I'll Never Smile Again" | Tommy Dorsey and His Orchestra with Frank Sinatra and the Pied Pipers |
| August 3 | "I'll Never Smile Again" | Tommy Dorsey and His Orchestra with Frank Sinatra and the Pied Pipers |
| August 10 | "I'll Never Smile Again" | Tommy Dorsey and His Orchestra with Frank Sinatra and the Pied Pipers |
| August 17 | "I'll Never Smile Again" | Tommy Dorsey and His Orchestra with Frank Sinatra and the Pied Pipers |
| August 24 | "I'll Never Smile Again" | Tommy Dorsey and His Orchestra with Frank Sinatra and the Pied Pipers |
| August 31 | "I'll Never Smile Again" | Tommy Dorsey and His Orchestra with Frank Sinatra and the Pied Pipers |
| September 7 | "I'll Never Smile Again" | Tommy Dorsey and His Orchestra with Frank Sinatra and the Pied Pipers |
| September 14 | "I'll Never Smile Again" | Tommy Dorsey and His Orchestra with Frank Sinatra and the Pied Pipers |
| September 21 | "I'll Never Smile Again" | Tommy Dorsey and His Orchestra with Frank Sinatra and the Pied Pipers |
| September 28 | "I'll Never Smile Again" | Tommy Dorsey and His Orchestra with Frank Sinatra and the Pied Pipers |
| October 5 | "I'll Never Smile Again" | Tommy Dorsey and His Orchestra with Frank Sinatra and the Pied Pipers |
| October 12 | "I'll Never Smile Again" | Tommy Dorsey and His Orchestra with Frank Sinatra and the Pied Pipers |
| October 19 | "Only Forever" | Bing Crosby with John Scott Trotter and His Orchestra |
| October 26 | "Only Forever" | Bing Crosby with John Scott Trotter and His Orchestra |
| November 2 | "Only Forever" | Bing Crosby with John Scott Trotter and His Orchestra |
| November 9 | "Only Forever" | Bing Crosby with John Scott Trotter and His Orchestra |
| November 16 | "Only Forever" | Bing Crosby with John Scott Trotter and His Orchestra |
| November 23 | "Only Forever" | Bing Crosby with John Scott Trotter and His Orchestra |
| November 30 | "Only Forever" | Bing Crosby with John Scott Trotter and His Orchestra |
| December 7 | "Only Forever" | Bing Crosby with John Scott Trotter and His Orchestra |
| December 14 | "Only Forever" | Bing Crosby with John Scott Trotter and His Orchestra |
| December 21 | "Frenesi" | Artie Shaw and His Orchestra |
| December 28 | "Frenesi" | Artie Shaw and His Orchestra |