The Canadian gold miner was previously involved in a months-long proxy fight with billionaire John Paulson's hedge fund, which pushed for a complete overhaul of the board and Kenyon's resignation.
Williams is a mining industry veteran and was a former CEO of gold and copper miner Orvana Minerals Corp.
He was one of five members elected to the Detour Gold board at a special shareholders meeting held on Dec. 13. These nominees were backed by Paulson, which alleged that under the leadership of Kenyon the company had "unsuccessfully tried to boost short-term performance".
Shares of the company were up 1.5 percent at C$11.93 in early trade.
(Reporting by Shanti S Nair in Bengaluru; Editing by Shinjini Ganguli)