The double Oscar-winner was on the live broadcast to promote his new film "Cloud Atlas." The expletive escaped his lips while he was speaking as a British character in the movie and talking about his boots.
"We are so sorry, 'Good Morning America,'" co-anchor Elizabeth Vargas said as guest Hanks looked shocked and covered his mouth.
"Man oh man. I have never done that before. I would apologize to the kids of America who are watching this right now. And the next time I'm on the show, there will be a 7-second delay. Never give me a handheld mic. I blame the staff."
Despite the star's apology, the Parents Television Council said it is unacceptable the F-word slipped through unedited during the broadcast.
"Once again, a morning news show has allowed the harshest profanity to be broadcast into every living room and breakfast table in the country," PTC director of public policy Dan Isett said in a statement.
"This is just another in a long, sad string of similar instances where all of the major network morning shows have permitted this inappropriate and offensive content," the statement said. "These cannot and must not be dismissed as 'mistakes,' and it's time for the networks to step up, take responsibility for what they broadcast, and ensure that this never happens again."