Clooney, 50, was married briefly in the 1990s but the marriage ended in divorce. He has since had numerous relationships with beautiful women but has shown no interest in remarrying. He is currently dating Stacy Keibler, an American actress and former professional wrestler.
The Oscar-winning actor also is a prominent campaigner for legalizing same-sex marriage in the United States.
"I think it's funny, but the last thing you'll ever see me do is jump up and down saying, 'These are lies!' That would be unfair and unkind to my good friends in the gay community," Clooney told gay and lesbian publication The Advocate.
"I'm not going to let anyone make it seem like being gay is a bad thing. My private life is private, and I'm very happy in it. Who does it hurt if someone thinks I'm gay? I'll be long dead and there will still be people who say I was gay. I don't give a [expletive]."
Britain's Daily Telegraph said rumors about Clooney's sexuality swirled after his friend Brad Pitt, also a supporter of the legalization of same-sex marriage, joked he would not wed his girlfriend Angelina Jolie until Clooney could legally marry his partner.
Clooney told The Advocate Pitt was "being funny about it because he knows that the best and most effective way to end marriage inequality is to point out the ridiculousness of it."