Walt Disney Studios chairman Alan Horn said in a statement that the tweets are indefensible and the studio has severed ties with Gunn.
Gunn has been writer and director of the Guardians Of The Galaxy franchise from the start.
He took an obscure Marvel Comics title about a group of misfits and turned it into two huge hits that together banked more than $1.5bn at the box office globally.
Gunn sent several tweets on Thursday saying he was sorry for trying in the past to get laughs through shock value.
In one, he said: “I used to make offensive jokes. I don’t anymore.
“I don’t blame my past for this, but I like myself more and feel like a more full human being and creator today.”
In another, he said: “In the past I have apologised for humour of mine that hurt people. I truly felt sorry and meant every word of my apologies.”
Gunn has been writing the script for Guardians 3 and the movie was expected to begin shooting in Atlanta soon with an expected 2020 release date.
His publicist did not immediately respond to an email requesting a comment.