What was Lady Gaga's first number one hit on the Billboard Hot 100?

Lady Gaga's first number-one hit on the Billboard Hot 100 was “Just Dance,” featuring Colby O'Donis. The song became her breakthrough U.S. chart success and eventually reached the top in January 2009.

“Just Dance” was released as the lead single from Gaga's debut studio album, The Fame. It entered the Billboard Hot 100 at number 76 in August 2008, then climbed gradually rather than becoming an immediate chart-topper. After 22 weeks on the chart, it reached number one for the first time on the January 17, 2009, chart.

The song’s slow climb is easy to overlook because Gaga soon followed it with another major success, “Poker Face.” “Poker Face” also topped the Hot 100, but it was her second number-one single there, not her first. “Bad Romance” arrived later and became one of her signature songs, while “LoveGame” was a successful hit without being her first Hot 100 number one.

Written by Gaga, RedOne, Akon, and others, “Just Dance” helped establish the dance-pop sound and visual identity that defined the beginning of Gaga’s mainstream career.