The award is voted for by journalists based in Asia and Europe with Sonny's form recognised for Bayer Leverkusen in the first part of 2015 and here at Spurs since his arrival from the Bundesliga in August.
Such a popular member of the squad, Sonny has scored five goals in 28 appearances in all competitions in his first season in England.
It's the second big Asian award for the forward after he was crowned AFC Asian International Player of the Year 2015 in December.
Below: Sonny speaks to Spurs TV after receiving the award
"This is the second time I’ve won the award, the first time I was with Leverkusen in Germany and now I’m here," said Sonny, whose award was presented by China's former City star Sun Jihai.
"It is very nice to have been voted the 2015 best player in Asia, I’m very happy and thankful for all of the fans at Tottenham and Leverkusen for their support over the last year.
Below: Sun Jihai presents Sonny with the award at Hotspur Way
“It was my dream to be voted the best player in Asia and I’m very happy about it. It’s not easy to win but I’m very happy.
“It has been a very good couple of years for me but I need to keep going, I need to work very hard to stay in this position (as number one player in Asia) and I hope that I can stay there."