Morrissey's manager has accusedof employing "harshly hateful tactics" after it mocked the singer in its latest episode.
The long-running cartoon featured Benedict Cumberbatch voicing a thinly disguised parody of the former Smiths frontman.
In the episode 'Panic On The Streets Of Springfield' — a reference to a 1986 Smiths song — Lisa was accompanied by an imaginary friend named Quilloughby, a sullen vegan singer who has become overweight and anti-immigrant.
Peter Katsis, Morrissey's manager, responded with a post on the star's Facebook page and said The Simpsons' writing had gone downhill.
The comedy has "degenerated to trying to capitalise on cheap controversy and expounding on vicious rumours", Mr Katsis wrote.
He noted thatstar Hank Azaria had recently apologised over the character of Apu, after the show was accused of making the Indian shopkeeper a racist stereotype, and Mr Katsis defended Morrissey, 61, against some of the jibes in the latest episode.
He wrote: "Morrissey has never made a 'cash grab', hasn't sued any people for their attacks, has never stopped performing great shows, and is still a serious vegan and strong supporter for animal rights. By suggesting all of the above in this episode... the Simpson's hypocritical approach to their storyline says it all. Truly they are the only ones who have stopped creating, and have instead turned unapologetically hurtful and racist. Not surprising... that The Simpsons viewership ratings have gone down so badly over recent years."
Morrissey, a revered figure for many, has alienated some fans with his outspoken and controversial views.
He once called halal meat "evil" and showed support for the far-right For Britain party during an appearance on Jimmy Fallon's TV show in May 2019.
Morrissey denies being a racist.
Before the episode aired,writer Tim Long said Morrissey, Joy Division's Ian Curtis, and The Cure's Robert Smith were all among the inspirations for Quilloughby.