The American singer also provides the highest new entry of the week, with her follow-up single 'Poker Face' debuting at number eight in the chart.
'Just Dance' knocks Alexandra Burke's 'Hallelujah' down to second position after four weeks at the top spot, while James Morrison's 'Broken Strings' holds steady at number three.
Beyoncé takes the remaining positions in the top five, with 'Single Ladies (Put A Ring On It)' and 'If I Were A Boy' securing fourth and fifth place respectively.
The star also tops the album chart with I Am... Sasha Fierce for a second consecutive week, followed by Kings Of Leon with Only By The Night at number two and The Script's self-titled debut disc at number three.
The top ten singles in full:
1. (2) Lady GaGa ft. Colby O'Donis: 'Just Dance'
2. (1) Alexandra Burke: 'Hallelujah'
3. (3) James Morrison ft. Nelly Furtado: 'Broken Strings'
4. (8) Beyoncé: 'Single Ladies (Put A Ring On It)'
5. (5) Beyoncé: 'If I Were A Boy'
6. (4) The Killers: 'Human'
7. (7) Kings Of Leon: 'Use Somebody'
8. (-) Lady GaGa: 'Poker Face'
9. (9) MGMT: 'Kids'
10. (6) Leona Lewis: 'Run'