Which 2008 song by Lady Gaga was her first number-one single in the US?

The 2008 Lady Gaga song that became her first number-one single in the United States was “Just Dance.” It was Gaga’s debut single and the lead release from her first studio album, The Fame.

Released in April 2008, the dance-pop track features additional vocals from Colby O’Donis and was produced by RedOne. Gaga wrote it with RedOne and Akon, reportedly creating the song in about 10 minutes as an upbeat club record. Its lyrics portray someone trying to keep dancing through a chaotic night out.

“Just Dance” was a slow-building hit rather than an immediate chart-topper. It entered the Billboard Hot 100 in August 2008 and reached number one in January 2009 after a 22-week climb. That achievement made it Gaga’s first US number-one song, although “Poker Face,” released afterward, is often remembered as the bigger early breakthrough.

The single became a major international success, topping charts in countries including Canada, Australia, the United Kingdom, and Ireland. In the United States, it was eventually certified multi-platinum by the RIAA.