The song spends its fourth week on top and has denied Delta Goodrem's new single 'Sitting On Top Of The World' a number one debut.
Goodrem settles at two, while Florence + the Machine are at three with 'Never Let Me Go' and Nicki Minaj slips to four with 'Starships'.
Ed Sheeran remains at five with 'Lego House', One Direction slide to six with 'One Thing' and Labrinth is down a place to seven with 'Earthquake'.
Rihanna zooms up to 12 with 'Where Have You Been', Calvin Harris and Ne-Yo land at 17 with 'Let's Go' and Justin Bieber is at 23 with 'Boyfriend'.
Pitbull is at 32 with Men In Black 3 soundtrack 'Back In Time', Lil Wayne is at 36 with 'Mirror' and James Morrison re-enters at number 40 with 'I Won't Let You Go'.
The Top 10 singles in full (click where possible for our reviews):
1. (1) Carly Rae Jepsen: 'Call Me Maybe'
2. (-) Delta Goodrem: 'Sitting On Top Of The World'
3. (18) Florence + the Machine: 'Never Let Me Go'
4. (2) Nicki Minaj: 'Starships'
5. (5) Ed Sheeran: 'Lego House'
6. (3) One Direction: 'One Thing'
7. (6) Labrinth ft. Tinie Tempah: 'Earthquake'
8. (4) fun. ft. Janelle Monae: 'We Are Young'
9. (10) One Direction: 'What Makes You Beautiful'
10. (13) Flo Rida feat. Sia: 'Wild Ones'
Watch Carly Rae Jepsen's 'Call Me Maybe' music video below: