The song, which has sold 1.28 million copies, peaked at number one on the UK singles charts in February and stayed there for five weeks.
Carly Rae Jepsen's 'Call Me Maybe' is the second biggest selling single, followed by Fun.'s 'We Are Young', ft. Janelle Monae and David Guetta's 'Titanium' ft. Sia.
Nicki Minaj's 'Starships' is in fifth position, despite not reaching the number one spot.
The official top ten biggest selling singles of 2012 so far are as follows:
1. Gotye ft. Kimbra - 'Somebody That I Used To Know'
2. Carly Rae Jespen - 'Call Me Maybe'
3.Fun. ft. Janelle Monae - 'We Are Young'
4. Davd Guetta ft. Sia - 'Titanium'
5. Nicki Minaj - 'Starships'
6. Jessie J - 'Domino'
7. Maroon 5 ft. Wiz Khalifa - 'Payphone'
8. Flo Rida ft. Sia - 'Wild Ones'
9. Psy - 'Gangnam Style'
10. Emeli Sandé - 'Next to Me'
Emeli Sandé has had a major impact on the charts this year, having also claimed the biggest selling album of the year so far on Thursday (November 29).
The Christmas number one position is yet to be decided, which could mean that the chart changes significantly. The run-up to Christmas is traditionally the biggest time of the year for single sales.
Watch the music video for 'Somebody That I Used To Know' below: