The actor died at the Wellington Hospital in London following a long illness, The Guardian reported.
“His family are very appreciative and completely overwhelmed by the outpouring of real love and affection being expressed towards him, and to us, during this unhappy time,” his daughter, Kate, said in a statement.
“Thank you all, from the bottom of our hearts. In due course there will be a memorial filled with song and good cheer, as he would have wished,” she said.
Mr. O'Toole announced his retirement from acting last year, bidding “the profession a dry-eyed and profoundly grateful farewell.”
Last month it was reported he had been coaxed out of retirement to act in a film about ancient Rome called “Katherine of Alexandria,” The Guardian reported.
He is survived by two daughters, Pat and Kate O'Toole, and his son, Lorcan O’Toole.