Duminy, roped in by Daredevils last season, was the franchise's star performer.
He was recently named South Africa's T20 captain.
"I'm grateful for the support and belief from the franchisee. It's an absolute privilege to lead such a talented mix of players. I am excited about the season ahead and sincerely hope we will be able to turn around the fortunes of Delhi Daredevils in the upcoming IPL season," read a statement from Duminy.
Daredevils head coach Gary Kirsten added: "J P (Duminy) is the right choice to lead the team for the upcoming season. He has the necessary experience and demeanour to take the team forward. I have seen him progress and mature as a player and leader through the years with the South African national team."
Image: Jean-Paul Duminy
Photograph: BCCI