No cause of death for John was reported.
The actor's death was announced by his daughter on Instagram on Sunday, in which she described him as the "brightest light in the world". "Imagine the best person in the world", Caitlin captioned a photo of her as a child in her father's arms. Now imagine that person being your dad. I spent so many years in #JohnReilly 's company, suffice to say he was a huge influence on me and I am forever grateful for his kindness and love. I'm so grateful I received to appreciate him. I know how much you loved him. "I love you forever Daddy".
The actor is also known for his runs as Del Douglas on Sunset Beach and as villain Alistair Crane on Passions. He took over the role of Dr. Dan Stewart on As the World Turns in 1974 from John Colenback.
Reilly joined GH in June 1984 as Sean Donely, a longtime pal of Robert Scorpio's (Tristan Rogers). Along with playing this character on the soap, the actor was also a part of Night Shift back in 2008.
Finola Hughes, who performs Anna and Alex Devane on the present, said of his passing: 'He was a significant brother to me.
"The entire General Hospital family is heartbroken to hear of John Reilly's passing", read a tweet on the show's Twitter account on Sunday. Our hearts go out to his family, friends and fans during this hard time.
Reilly is survived by his wife, Liz, and his three daughters, two of whom from a previous marriage.
In the show, his character had several storylines in which he went from a bad guy to a good one.