"The offensive attitudes and statements discovered on James' Twitter feed are indefensible and inconsistent with our studio's values, and we have severed our business relationship with him," Walt Disney Studios chairman Alan Horn said in a statement Friday, according to The Hollywood Reporter.
Gunn also issued a statement Friday, saying he's a "very, very different" person than he was a few years ago and that he's "developed as a person" since he posted the offensive tweets.
"My words of nearly a decade ago were, at the time, totally failed and unfortunate efforts to be provocative," he said. "I have regretted them for many years since — not just because they were stupid, not at all funny, wildly insensitive, and certainly not provocative like I had hoped, but also because they don't reflect the person I am today or have been for some time."
“I used to make a lot of offensive jokes. I don’t anymore,” he said.
Gunn was fired before a scheduled appearance Friday at Comic-Con International: San Diego.
He was still writing the script for “Guardians of the Galaxy Vol. 3” and was expected to start shooting the movie this fall in Atlanta.
Disney and Marvel Studios saw huge successes with the "Guardian" movies, with the first one making more than $773 million and the second raking in $863, according to THR.