The actor, who voices long-standing characters Mr Burns, Ned Flanders, Principal Skinner, Waylon Smithers, Kent Brockman, and Reverend Lovejoy, tweeted the news, saying his contract had not been renewed.
“From James L Brooks’ lawyer: Show will go on, Harry will not be part of it, wish him the best.
“This because I wanted what we’ve always had: The freedom to do other work.
“Of course, I wish him the very best.”
from James L. Brooks' lawyer: "show will go on, Harry will not be part of it, wish him the best.". (1/2)— Harry Shearer (@theharryshearer) May 14, 2015
This because I wanted what we've always had: the freedom to do other work.— Harry Shearer (@theharryshearer) May 14, 2015
Of course, I wish him the very best. (2/2)
A few hours later, he tweeted: “Thanks, Simpsons fans, for your support.”
Thanks, Simpsons fans, for your support.— Harry Shearer (@theharryshearer) May 14, 2015
20th Century Fox, which produces the show, has not released a comment.
However, residents and visitors to West Cork may hear a familiar voice in their local pub and restaurant, as Shearer is understood to have bought a house in Ahakista.
He has been a regular visitor to these shores because of his wife’s Irish connections — her sister lives in Wexford.
Shearer is also friends with Graham Norton, who is from Bandon, Co Cork.
Rumours suggested that one actor was not signed up to the newly announced 27th and 28th seasons of The Simpsons due to disputes over profit-sharing and merchandising. However, Shearer was not named.
TMZ indicated that Shearer was the last cast member to sign a two-year extension to his contract because he has disputed “back-end and merchandising parts” since October.
He reportedly refused to sign the contract, while all other members of the cast took on the new terms.
The departure of Shearer will be a major blow to the show, with many fans questioning how it can continue without key character voices which have featured in the show since 1989.
Shearer’s exit also raises questions about the sense of continuing the show for another two seasons, when some episodes from season 26 dipped below 3m viewers for the first time.
In October 2013, the show lost Marcia Wallace, who voiced the character of Edna Krabappel, Bart Simpson’s teacher. She died aged 70.
Last year, comedian Jan Hooks, who was the voice of Apu’s wife Manjula, died after contracting cancer.