The performer was awarded the gong in Mumbai at the annual event.
On accepting the honour, King said: "Thank you. What a year. Bollywood has shown me so much love. I'm touched. Here's to more songs, more magic. Thank you, Stardust. Thank you to the fans.
"It has been a great year for my songs, especially 'Te Amo' and 'I Love You', big thanks to Pritam for that. AR Rahman introduced me to the industry and I am ever grateful. It is an honour to be part of this industry."
King won the award over Ali Zafar, Kamal Khan and Shahid Mallya, all of whom featured in the same category.
The London artist delivered an a cappella version of the Bodyguard track 'I Love You'. Ek Main Aur Ekk Tu star Kareena Kapoor also featured King's 'Aunty Ji' during a stage show peformance at the awards.
The event was also attended by veteran actor Rekha, and stars including Akshay Kumar, Deepika Padukone, Vidya Balan, Kajol, Kareena Kapoor and Bipasha Basu.
Watch the video for Ash King's 'I Love You' below: