Michael Lewis will take the helm of E.On UK following current chief executive Tony Cocker's retirement.
Lewis, who has led E.On's climate and renewables arm since 2015, will start the new position from 10 April.
"It is a fascinating time to take on this challenge and a real privilege to follow Tony, who has ensured E.On UK is leading the change needed to ensure we live up to our purpose of improving peoples’ lives," Lewis said.
Cocker has worked for E.On for more than 20 years, and he's been the firm's UK chief exec since September 2011. He is retiring to pursue a portfolio career, according to a statement from E.On.
"Having spent five years in post I decided it was time to take on new challenges and I am personally delighted that Michael is to succeed me," Cocker said.
The boss of E.On, Johannes Teyssen, said: "I’d like to thank Tony Cocker for his outstanding contribution, not only to our UK business but also to our company as a whole. During his time leading our UK business, Tony helped make customer focus part of our DNA. The management board wishes Tony and his family all the best for the future."
Earlier this month, the Germany-based company increased prices for dual fuel customers in the UK by £97 a year because of increasing costs to social and environmental schemes.