The 40-year-old has filled in for the 63-year-old several times in the past. She most recently stepped in last month, and was also seen on Ellen in October.
"Tiffany is a favorite, she has humor and empathy in spades," a senior NBCUniversal source said. "She’s top of the list to get a daytime show — she’s a fresh voice."
DeGeneres reportedly owns the rights to her show, which is produced and syndicated by Warner Bros. This means that Haddish or another host cannot step in to replace DeGeneres, but instead a new host and show would be needed.
Haddish has also been seen on Kids Say The Darndest Things on CBS. The Kelly Clarkson Show is also reportedly a favorite to take over DeGeneres' 3 p.m. time slot.
According to THR, season 19 will be the end of the show. "The ratings have tanked and have been truly appalling this year and Ellen knows her time is up," an insider said.
"While we are disappointed, we are extremely supportive of Ellen’s decision to end her show next season," Warner Bros. TV Group chairman Channing Dungey said. "Ellen once said that all she ever wanted to do was make people feel good and laugh, and she has accomplished that and so much more."
It has been heavily speculated that the end is due to an ongoing toxic work environment scandal, but DeGeneres said if that was the case she would not have returned for season 18. "So, it’s not why I’m stopping," the Finding Dory star said.
DeGeneres said she wanted to end the show after season 16 but was urged to continue by producers and "we [settled] on three more years and I knew that would be my last. That’s been the plan all along."
DeGeneres initially thought the toxic workplace scandal was "hilarious" when the first allegation was made but then more followed. "I didn’t want to address it on [Twitter] and I thought if I just don’t address it, it’s going to go away," she admitted.
DeGeneres then said she found out about the allegations through the press and "it broke my heart when I learned that people here had anything other than a fantastic experience," after an internal investigation.
While the current season started off strong, it has reportedly been declining ever since. According to the Daily Mail, ratings in New York City and Chicago are down 40%, Ellen lost 59% of her Los Angeles viewers, went down 32% in Philadelphia and lost 50% of her San Francisco viewers.
Page Six was the first to report that Haddish is being eyed for the slot.