Ellen DeGeneres says she's found the One. In the December issue of O: The Oprah Magazine, DeGeneres, 51, tells Oprah Winfrey that she and Portia de Rossi "are perfect for each other."

The comedian, talk show host and American Idol judge (come this January) opens up to Winfrey about actress de Rossi, 36, with whom she's been in a relationship since 2004. "She is so beautiful and so smart and so funny," DeGeneres gushes.

"I have that sense of 'I'm done now.' I'm settled," she says. "I know that part of my life is taken care of. I've got love. I've got someone who will be with me till the day I die."

The couple married on Aug. 16, 2008 in a small ceremony in their home; because their wedding took place before the November 2008 passage of Proposition 8 (banning gay marriage in California), a Supreme Court judgment upheld the legality of their union.

DeGeneres also talked to Winfrey about her upcoming gig alongside Simon Cowell, Randy Jackson and Kara DioGuardi as an American Idol judge -- replacing Paula Abdul, who left the show after its eight season.

"They came to me, and it was a total surprise," she explains. "I like to try new things because I get bored so easily. And I like the show, so I thought it was a great idea."

The ninth season of American Idol premieres in January 2010.