EastEnders boss quits after 'exhausting' two years
Bryan, the programme's executive producer, said he had decided to move on after his stint in one of the most exciting, but 'exhausting' jobs in TV.
The programme boss previously worked on Coronation Street and Hollyoaks before taking up his BBC role in March 2010.
Series producer Lorraine Newman will take on his role on an acting basis.
Under Bryan the show saw the return of Kat and Alfie Moon to Albert Square, as well as the arrival of fresh characters such as Derek Branning.
He said: "Being the executive producer of EastEnders is one of the most exciting jobs in TV, but it's also the most exhausting - so after two years, I've decided it's time to leave Walford.
He said it had been a 'thrill' to work with the programme team, adding: "Most of all it's been a privilege to tell stories that have genuinely had the nation talking."
John Yorke, the BBC's controller of drama production, said: "I would like to thank Bryan for his extraordinary hard work, a chest full of awards and some great storylines.
"It's been a pleasure working with him and I wish him every success for the future."