Hugh Morris is quitting as managing director of the England and Wales Cricket Board to take on a dual role with Glamorgan.
Former Glamorgan captain Morris, 49, has been appointed as the county's chief executive and managing director.
He replaces chief executive Alan Hamer, who leaves at the end of the season.
"I really enjoyed my time as a player with Glamorgan and now my task is to work with everyone at the club to increase our talent pool," Morris said.
He added that he was "very grateful" to Glamorgan chairman Barry O'Brien and the committee of Glamorgan for "providing me with this opportunity and a new and exciting challenge at this stage of my career".
Morris joined the ECB as technical coaching director in 1997, before becoming acting chief executive and deputy chief executive.
He was appointed managing director of cricket in 2007, overseeing three consecutive Ashes series victories over Australia.
"This has been a remarkable period in the history of cricket in England and Wales and I have been extremely proud to have been able to play a part in it," he said.
"I am now looking forward to a new and exciting challenge with Glamorgan, which I will tackle with energy, enthusiasm and relish."
Morris believes former England captain Andrew Strauss or current England's team director Andy Flower would be ideal successors as managing director of England cricket.
"I've not spoken to Andrew about it but he is an incredibly capable man," said Morris.
"Both Andy Flower and Andrew Strauss are fantastic guys, I know them both well and I worked with them for a long time.
"Whatever job either of them wants to do they will do very well, no doubt about it.
"If they fancied this job, or applied, either of them would be great but that is for others to decide."
Flower said Morris would be "sorely missed" and added that he would need to be replaced "by a man of equal calibre".
Morris retired as a Glamorgan player in 1997 to join the ECB.
He led Glamorgan to the Sunday League title in 1993 - the county's first silverware in 29 years - and played an important role in their 1997 County Championship success.
The Sunday League triumph came during his second spell as skipper. In 1986, he had become Glamorgan's youngest captain at the age of 22, stepping down three years later to concentrate on his batting.
A left-handed opener, Morris scored 19,785 first-class runs, including 53 centuries. He played three Test matches for England.
"We are delighted to have been able to appoint a person with the calibre of Hugh Morris, who has achieved so much as managing director of England cricket," said O'Brien.
"In addition to being a very fine player, he has demonstrated in his many roles at the ECB that he is also an administrator of the highest ability."
Hamer was appointed to the chief executive's role in 2009 but has been with the county since joining as finance and commercial director in 2006.
Hamer's resignation comes less than a week after Matthew Mott announced he would leave his post as Glamorgan's elite performance director.
O'Brien paid tribute to the work Hamer had done at the Swalec Stadium.
"Alan has indicated to me for a while that he wishes to pursue a number of other opportunities," said O'Brien. "I am very grateful to Alan and respect his decision to seek a new challenge."