List of Billboard Hot 100 number ones of 1959

The Billboard Hot 100 is a chart published by Billboard magazine which ranks the best-performing singles in the United States. In 1959, it was compiled based on a combination of sales and airplay data sourced from surveys of retail outlets and playlists submitted by radio stations respectively, and 16 different singles spent time at number one.

In the issue of Billboard dated January 5, the Chipmunks with David Seville were at number one with "The Chipmunk Song", the single's third week in the top spot. The single remained at number one for a further week before being displaced by "Smoke Gets in Your Eyes" by the Platters in the issue dated January 19. Not until 2019 would another Christmas song top the Hot 100, albeit for much of the 1960s, 1970s, and 1980s holiday-themed songs were excluded from the chart.

Every act to top the Hot 100 in 1959 did so for the first time since the chart was launched in August 1958. The Platters, Paul Anka, Elvis Presley, and Guy Mitchell had all achieved number ones on the separate sales, airplay, and jukebox play charts which Billboard had published prior to the creation of the consolidated Hot 100, as had Seville without the Chipmunks. The Fleetwoods and Frankie Avalon were the only acts to have two number ones in 1959, but neither act would top the Hot 100 again. Bobby Darin spent nine non-consecutive weeks at number one with "Mack the Knife", making it the year's longest-running number one and Darin the act with the most weeks in the top spot. At the 2nd Annual Grammy Awards in November 1959, the song won the award for Record of the Year, but it would prove to be Darin's only number one on the Hot 100. In the first of its two spells atop the chart, "Mack the Knife" spent six weeks at number one, tying with "The Battle of New Orleans" by Johnny Horton for the year's longest unbroken run in the peak position.