The singer-songwriter, real name Wouter De Backer, climbs from three to earn his first number one single, fending off Maroon 5 and Christina Aguilera's 'Moves Like Jagger', which remains at two.
Elsewhere, Jessica Mauboy leaps from ten to four with 'Inescapable', and LMFAO's 'Champagne Showers' advances from 11 to ten.
Further down the chart, Pitbull and Marc Anthony's 'Rain Over Me' climbs from 17 to 11, Rihanna's 'Cheers (Drink to That)' zooms 46 to 18, and David Guetta and Sia's 'Titanium' lands at 31.
Marvin Priest and Wynter Gordon's 'Take Me Away' enters at 32 and Hot Chelle Rae's 'Tonight Tonight' starts at 43.
The Top 10 singles in full (click where possible for our reviews):
1. (3) Gotye ft. Kimbra: 'Somebody That I Used To Know'
2. (2) Maroon 5 ft. Chrisitina Aguilera: 'Moves Like Jagger'
3. (1) Adele: 'Someone Like You'
4. (10) Jessica Mauboy: 'Inescapable'
5. (4) LMFAO ft. Lauren Bennet & GoonRock: 'Party Rock Anthem'
6. (7) Nicki Minaj: 'Super Bass'
7. (6) Adele: 'Rolling In The Deep'
8. (8) Nicole Scherzinger ft. 50 Cent: 'Right There'
9. (5) Christina Perri: 'Jar of Hearts'
10. (11) LMFAO ft. Natalia Kills: 'Champagne Showers'
Watch Gotye's 'Somebody That I Used To Know' video below: