Prime Minister Jacinda Ardern awarded him the honour at the 10th annual edition of the awards.
Last year's winner Kristine Bartlett and 2014 winner Dr Lance O'Sullivan presented him the Kiwibank kaitaka huaki cloak, Pouhine.
"Mike King is a wonderfully complex and compelling Kiwi," chief judge Cameron Bennett said last year.
"His determination to shine a light on the effects and impacts of mental health, particularly among Maori and young people, is as uncompromising as it is confronting.
"His passion and total commitment challenges us to think again about how we address some of the most serious social issues of our time."
A total of 448 nominations were received for the title and the judges decided King was the right answer for this year's award.