The unidentified representative told People magazine exclusively Saturday that the celebrity couple were married during an intimate ceremony attended by a scant 19 guests.
"Ellen DeGeneres and Portia de Rossi were married tonight in an intimate ceremony at their home in Los Angeles," the representative said.
The couple, who have been dating since December 2004, exchanged handwritten vows during the ceremony.
DeGeneres announced in May during a taping of "The Ellen DeGeneres Show" that she and the former "Arrested Development" star decided to marry once California legalized gay marriage.
People said the 50-year-old talk show host said in 2007 that her relationship with the 35-year-old actress has been beneficial to them both.
"She's taught me lessons about myself, and I feel like I've taught her," DeGeneres said. "We've both changed and grown, and we just feel like, 'Oh, OK, this is completion.'"