On Tuesday, Daredevils announced that Pietersen will lead the side and wicketkeeper-batsman Dinesh Karthik will be his deputy.
"I feel incredibly honoured to have been asked to captain the Delhi Daredevils in this year's IPL," said Pietersen on his appointment.
"I am very much looking forward to working alongside Gary Kirsten. We have a fantastic squad with a good blend of youth and experience and a brilliant coaching set up," he added.
Pietersen, who was sacked as England player recently, will be available for the full season of IPL. The 33-year-old right-hander was bought by Delhi for Rs 9 crore (used right to match card) during last month's auction in Bangalore.
Pietersen joined Daredevils in 2012 and made an impact with his eight-match outing amassing 305 runs with an average of 61.
He was unavailable in 2013 due to an injury but made it a point to visit the team and spend valuable time with the youngsters in the squad.
Karthik makes his return to the Daredevils family after having played with the franchise for the first three years. He was bought for Rs.12.5 crore at the auction.
The wicket-keeper batsman has amassed 1,741 runs in 92 IPL appearances.
On the appointments, Kirsten said: "I am looking forward to working with Kevin Pietersen as the captain of the Delhi Daredevils. It will be great to have him with us for the full duration of IPL and I have no doubt that he will have a positive and significant impact."
This edition's IPL will begin on April 16 in the United Arab Emirates (UAE).