India's Virat Kohli took the one-day player of the year honour and West Indies off-spinner Sunil Narine was named emerging cricketer of the year.
Sangakkara scored 1,444 runs in 14 test matches between August 2011 and August 2012 at an average of 60.16, with five centuries and five half-centuries.
He also amassed 1,457 runs at 42.85 from 37 one-day internationals in the same period, during which he picked up 42 dismissals as his country's wicketkeeper.
The 34-year-old edged out a shortlist of South Africa's Hashim Amla and Vernon Philander and Australia's Michael Clarke to win the award.
"This is an amazing honour," said Sangakkara, who also won the people's choice award.
"I've seen the people who have won it before me and the nominees too, to be named alongside them is wonderful. I admire them greatly and even more so when I looked up at their records on the screen this evening."
India's Kohli was named one-day cricketer of the year for his 1,733 limited-overs runs at an average of 66.65.
He said: "I think I have tried to keep things as simple as possible and it's worked for me on the field. This year has been a learning curve along the way from the seniors in the team. It's been an all-round effort and I'm very happy to have won this award."
Narine, 24, from Trinidad, claimed 12 wickets at 31.50 from three test matches for the West Indies.
South African batsman Richard Levi won the international Twenty20 performance of the year award for his 51-ball 117 not out against New Zealand in Hamilton in February.
The awards were slightly overshadowed by Pakistan spinner Saeed Ajmal not being nominated for an individual award despite his heroics over the last 12 months. Pakistan in the end decided not to boycott the ceremony.
The World Twenty20 takes place in Sri Lanka between Sept.18 and Oct.7. - AGENCIES