The 24-year-old cites influences from Bob Dylan to Miles Davis and has a voice that has been compared to that of Bill Withers.
Kiwanuka has already supported Adele on tour and claimed a slot on Later... with Jools Holland. He is the tenth act to top the BBC's Sound of list with previous winners including Jessie J, Adele, Mika, Ellie Goulding, Corinne Bailey Rae and Keane.
"It's very encouraging for some of my music to be noticed and considered as something worth listening to," said Kiwanuka.
"I think it's every musician's dream to have any sort of recognition for their art, something that is so personal. This is something that I don't take for granted.??
"I hope I can fulfil some of people's expectations, but most importantly I hope people that enjoy my music feel like they can get something worthwhile from listening to it," he added.
The list was compiled using tips from 184 influential tastemakers, who each named their favourite three new acts from any country and any musical genre.
David Smyth, chief rock and pop critic of the London Evening Standard, who took part, said: "I picked Michael because his music really grabbed me when I first heard him last summer.
"Paul Butler of The Bees produced his song Tell Me a Tale, giving it a vintage psychedelic soul feel. It was an unusual backdrop for such a rich, warm voice."
The full BBC Sound of 2012 top five is as follows:
1. Michael Kiwanuka
2. Frank Ocean
3. Azealia Banks
5. Niki & The Dove
Also on the longlist (unranked) were:
Dry The River
Jamie N Commons
Lianne La Havas