A little more than a month after Paula Abdul tendered her high-profile Twitter resignation as a judge on “American Idol,” Fox announced Wednesday that she was being replaced by one of the show’s biggest fans, comedian and talk-show host Ellen DeGeneres. The network’s five-year deal with DeGeneres puts to rest a major challenge facing Fox as the aging singing competition enters its ninth season in January: filling the shoes of the judge considered by many to be the heart of the show. DeGeneres, who has hosted the Oscars and the Emmys and was recently a guest judge on Fox’s “So You Think You Can Dance,” broke the news to her audience during a taping of “The Ellen DeGeneres Show” on Wednesday. “I don’t know how it happened myself, but I have not missed one episode of that show,” DeGeneres said in the episode of the talk show that airs today. “I love everything about it and I love music, as you know. Hopefully I’m the people’s point of view because I’m just like you. I sit at home and I watch it and I don’t have that technical . . . I’m not looking at it in a critical way from the producer’s mind. I’m looking at it as a person who is going to buy the music and is going to relate to that person.” The move to sign DeGeneres came after a series of guest judges filled in for Abdul during the “Idol” audition rounds, including Spice Girl Victoria Beckham, singers Mary J. Blige, Katy Perry and Avril Lavigne, and actors Neil Patrick Harris and Kristin Chenoweth. DeGeneres will join Simon Cowell, Randy Jackson and Kara DioGuardi on the panel when the show returns to the air in January. It hasn’t been decided whether DeGeneres will join the other judges for pretaped semifinal rounds in November. The mating dance between Fox and DeGeneres began in earnest after she was a guest judge on “So You Think You Can Dance” in July. Although Abdul had not resigned at that point, DeGeneres’ appearance stuck with Fox executives, who were well aware that Abdul was not a lock to return. DeGeneres has long ties with Fox and landed one of her big breaks on the network 20 years ago in the short-lived comedy, “Open House.” Talks heated up late last week among Fox and DeGeneres and Warner Bros., which needed to give its blessing since it has an exclusive TV contract with DeGeneres. Leading negotiations for DeGeneres were ICM agent Eddy Yablans and manager Caryn Weingarten, who found a receptive audience at Fox, where Tony Vinciquerra, chief executive of the Fox Network Group, gave the green light to new entertainment chairman Peter Rice to get a deal done. Rice, working closely with reality programming chief Mike Darnell and business affairs head Ira Kurgan, quickly put together a multiyear contract that would bring stability to TV’s No. 1 show, both in front of and behind the camera. Though Warner Bros., which produces and distributes DeGeneres’ talk show, did not stand in the way, the studio did extend its own deal with her for three more years — until 2014 — before agreeing to let her take on “American Idol.” “I’m going to have a day job and a night job,” DeGeneres said during her show. “The times we’re living in . . . we’re all doing that. This is so exciting for me. We’ve been dealing with this for the last couple of weeks and I’ve been dying to tell everyone. It’s just been so hard to keep it a secret and we just finally got the OK and I’m so excited.” Signing DeGeneres will likely make it easier for Fox to make a deal with Cowell, whose contract expires next May. Though rumors have persisted that Abdul and Fox might come to terms in time for her to be back by “Idol’s” January return, her manager, David Sonenberg, told The Times) last month that chances of such a scenario playing out were slim. Abdul has since made deals to host the “VH1 Divas” ceremony. Her guest spot on the Lifetime comedy “Drop Dead Diva” has turned into a recurring role. She also told “Access Hollywood” that she is working on a deal to develop and star in her own Las Vegas revue. After failing to clinch a more lucrative deal with “Idol,” Abdul tweeted her resignation Aug. 4. “With sadness in my heart, I’ve decided not to return,” she wrote. “I’ll miss nurturing all the new talent.” During the Television Critics Press Assn. tour last month, Fox executives said they were set on maintaining the four-judge arrangement even with Abdul’s departure. “I think that the four judges were getting in a rhythm last year, and we will probably have four judges back,” Rice said. “We have from now until January to introduce a different energy into the panel. . . . There is going to be a search, and we have to cast that in a way that is fun and energizing and creates some real chemistry between the people on the panel.” During an interview with Cowell on her talk show before the “Idol” season ended, DeGeneres told Cowell she wasn’t thrilled about the addition of a fourth judge: “I think everybody liked it the way it was with you and Randy and Paula. And all of a sudden there’s a fourth judge. It gives you less time to talk. It kind of splits it up.” Looks like someone has changed her mind.