The US pop singer - real name Stefani Germanotta - leaps to number one this week with her debut single 'Just Dance'.
'Just Dance', which features a cameo from New York rapper Colby O'Donis, also leads the US singles chart this week.
James Morrison and Nelly Furtado climb to two with 'Broken Strings', while Burke falls to three with her version of 'Hallelujah'.
Meanwhile, The Saturdays jump from 27 to six with 'Issues' to score their third consecutive top ten hit.
Other new tracks in the top ten come from Beyoncé, who climbs from 14 to eight with 'Single Ladies (Put A Ring On It)', and Kevin Rudolf, who zooms from 40 to ten with his debut single 'Let It Rock'.
The top ten singles in full (click to read our reviews):
1. (3) Lady GaGa ft. Colby O'Donis: 'Just Dance'
2. (5) James Morrison ft. Nelly Furtado: 'Broken Strings'
3. (1) Alexandra Burke: 'Hallelujah'
4. (2) Leona Lewis: 'Run'
5. (6) Kings of Leon: 'Use Somebody'
6. (27) The Saturdays: 'Issues'
7. (4) Beyoncé: 'If I Were A Boy'
8. (14) Beyoncé: 'Single Ladies (Put A Ring On It)'
9. (7) Katy Perry: 'Hot N Cold'
10. (40) Kevin Rudolf ft. Lil Wayne: 'Let It Rock'
Source: Official Chart Company
Click here for this week's UK albums top ten