The ITV duo backed up JK in an explosive Good Morning Britain row over transgender rights.
Over the weekend, Twitter was set alight in rage over claims JK Rowling' latest book Troubled Blood, written under her pseudonym Robert Galbraith, contains a transgender killer.
#RIPJKRowling was quickly trending online with many calling for the literary legend's books to be burned.
Hitting out during a four way debate live on GMB, Piers said: "This is the problem with cancel couture. People try to shame and destroy and ban and boycott.
"We had Jedward calling for the book to be burned... they hadn't read it either.
"Activists want to have a target. She has been a victim of a cancel culture.
"There have been calls for her publisher to drop her and for her Twitter account to be removed."
After activist Benjamin Butterworth claimed that JK hasn't 'been cancelled' and instead her words are dangerous to the trans community, Piers hit back: "You just said you don't want people to buy her book when you have not read the book."
Agreeing, Susanna added: "This is about a character which doesn't exist."
Chiming in, former MP George Galloway continued: "The irony is this will put it to the top of the best seller list.
"Can't people see the danger of policing fiction and how dangerous it is."
Trying to hammer his point home, Benjamin said: "The point is that when so few people know about trans people, the idea that the only supposed representation of a trans person is that they are a killer who dresses as a woman in order to kill."
Not giving in, Piers continued to vent: "The point is Benjamin, I don't even like her.
"I have had loads of run-ins with her. I have no reason to defend her but I do defend her right to free speech.
"You want her cancelled for a book you have not read.
"If I was to write a novel is your position that I would not be allowed to make it a transgender killer as that doesn't seem very equal."
Determined to have the final word, Piers added: "The tolerant with the woke brigade are not remotely tolerant."
Good Morning Britain airs weekdays on ITV at 6am