Walker announced in San Francisco his decision to overturn Proposition 8, a measure that reversed a California Supreme Court ruling that laws prohibiting same-sex marriage violated the state constitution.
In a statement issued to the Advocate.com, a publication targeted to a gay audience, entertainer Liza Minnelli praised Wednesday's ruling.
"Today's ruling in California encourages me to believe that people are beginning to understand that if you want to be with someone, protect them, and care for them through vows and the legalities of marriage, then you should be able to do that. Wonderful news," Minnelli said.
UsMagazine.com reported sisters Kim and Khloe Kardashian, Ellen DeGeneres and wife Portia De Rossi, and Paris Hilton took to the Web to cheer the decision.
"This just in: Equality won!" DeGeneres, who married De Rossi in 2008 before Prop. 8 was passed, said via Twitter.
"I am ecstatic that proposition 8 has been overturned in the state of California. This is an incredibly exciting and historical day and a big step towards equal rights for all," she said.
"This news is amazing! Its about time! Congrats to everyone!" Kim Kardashian tweeted.
"I know we're still not out of the woods here and the decision will likely be appealed and taken to Supreme court but that doesn't mean today isn't a day to celebrate dolls! So go out and party and be merry with the people you love," Khloe Kardashian said on her blog.
"What a huge historical day for equal rights in this country! They finally overturned Prop 8! There shouldn't be a law on true love," Hilton said.
UsMagazine.com said Britney Spears, Kelly Osbourne, Lance Bass, Seth Meyers, Pink, Nia Vardalos, Ricky Martin, Solange Knowles and Samantha Ronson also made statements Wednesday supporting the decision.