The singer and producer had hit singles with 'Bounce' and 'Feel So Close' as a lead artist in 2011, with both reaching number two on the UK chart.
However, it was his collaboration with Rihanna on 'We Found Love' which clinched his title, as the track became an international smash, reports Music Week.
Songwriting threesome The Smeezingtons - which includes Bruno Mars - came in second place, while Adele came third due to her huge sales of 21.
Ed Sheeran placed fourth following the release of his debut album + and his breakthrough hit 'The A Team'.
Norwegian hit-makers Stargate came fifth after working on projects with Rihanna, Alexis Jordan and Wiz Khalifa throughout 2011.
Harris and Rihanna have announced plans to play a charity gig in Los Angeles on February 12 in aid of the Children's Orthopaedic Centre.
> Calvin Harris, Jessie J, Labrinth for Wireless festival 2012
Watch the music video for Calvin Harris's hit 'Feel So Close' below: