The world leader had steered clear of openly stating his stance on the sensitive topic ahead of the November (12) general election, but he responded to growing pressure on Wednesday (09May12) and announced his endorsement of same-sex unions in a taped TV interview for ABC News.
Obama, who previously believed marriage should be between a man and a woman, told newscaster Robin Roberts: "I've been going through an evolution on this issue. I've always been adamant that gay and lesbian Americans should be treated fairly and equally. At a certain point, I just concluded that for me, personally, it is important for me to go ahead and affirm that I think that same sex couples should be able to get married."
The big announcement was warmly received by a slew of celebrities and they took to Twitter.com to celebrate the news.
Farrow writes, "YAY!!!! President Obama comes out in support of gay marriage !!!!", while lesbian singer Wright tweeted, "The President has just stated publicly that he believes 'same sex marriage should be legal'. I am proud. Thank you @BarackObama".
Actress Eliza Dushku posts, "Breaking: President Obama announces support for ALL/equal marriage!! FreedomToMarry" and Billy Elliott star Jamie Bell writes, "Good for you Mr. Obama. Good for you."
Married lesbian funnywoman Ellen DeGeneres tweets, "Thank you President @BarackObama for your beautiful and brave words. I'm overwhelmed", and Banks adds, "A fierce day for my gays and my prez @BarackObama - way 2 stand up 4 luv for ALL (sic)!"
Bisexual actress Evan Rachel Wood and gay stars Neil Patrick Harris and Sean Hayes were also among the first few celebrities to applaud the groundbreaking news on Wednesday.
Obama's endorsement comes just one day after residents in North Carolina passed a bill banning same-sex unions in the state, declaring marriage between a man and a woman the only valid domestic legal union.