"Roseanne's Twitter statement is abhorrent, repugnant and inconsistent with our values, and we have decided to cancel her show," ABC said in an official statement.
Disney CEO Bob Iger also tweeted, "There was only one thing to do here, and that was the right thing."
Barr wrote of African-American former Obama administration adviser Valerie Jarrett, "Muslim brotherhood & planet of the apes had a baby=vj."
She at first defended her comment, tweeting "It's a joke" and "Muslims r NOT a race." Then, she apologized, writing, "I apologize. I am now leaving Twitter."
Barr followed that up with an official apology.
"I apologize to Valerie Jarrett and to all Americans. I am truly sorry for making a bad joke about her politics and her looks. I should have known better. Forgive me-my joke was in bad taste."
After Barr's comments, comedian and consulting producer Wanda Sykes tweeted that she was leaving the show.
Actress Sara Gilbert, who plays Barr's daughter, also expressed her disappointment.
The Roseanne reboot debuted to 18 million live viewers and critical acclaim upon its debut, but its star dragged it into controversy with incendiary tweets.
One tweet accused a Parkland school shooting survivor of giving a Nazi salute, and another promoted a conspiracy theory that accused major Democratic leaders of having a role in a child sex trafficking ring.
ABC had previously renewed Roseanne for an 11th season.