Tarmey, who joined the soap in 1979, said he had enjoyed "great storylines"
Bill Tarmey, who plays Jack Duckworth in Coronation Street, is to leave the ITV soap after more than 30 years.
Fans of the show have been promised a "fitting" departure for the popular character, but producers have not revealed any details.
Tarmey, 69, who became one of TV's best loved duos with his screen wife Vera, said he would "be sorry to say goodbye to Jack".
He will stay on TV screens for the show's 50th anniversary in December.
Tarmey's decision to retire follows the departure of actress Liz Dawn, who bowed out of the soap opera in 2008 after playing Vera Duckworth for more than 30 years.
He said playing Jack had been "amazing".
"People often ask me if I like Jack Duckworth and I always reply - 'like him, I bloody love him'," said Tarmey.
"Because of him I have made some fantastic friends and travelled all over the world and I will be sorry to say goodbye to Jack."
An ITV spokesman said scriptwriters and new producer Phil Collinson were working on Jack's final storyline.
Jack and Vera were one of the most enduring TV partnerships
Tarmey added: "I had originally wanted to retire last year but producer Kim Crowther and my wife Ally persuaded me to stay for the show's 50th anniversary and I am glad that I made that decision.
"I have had some great storylines over the past three decades and I am looking forward to seeing what Jack's final story will be."
Coronation Street executive producer Kieran Roberts said: "Bill Tarmey and Jack Duckworth have been a huge part of Coronation Street for 30 years and, like his many millions of fans, everyone who works on the show with Bill will be sad to see him go.
"That said, we fully respect Bill's decision to retire and, when he leaves Coronation Street at the end of this year, we will make sure his character's send-off is fitting for one of the show's all time greats."
Tarmey has battled with his health in recent years, and has been seen less frequently on screen.
He suffered a minor heart attack following a bypass operation in 2002.
That came 15 years after a previous quadruple heart bypass.