In a new interview with The Hollywood Reporter, the comedian -- who was a panelist on "The View" from 2006 to 2007 -- said she had an argument with the late journalist after Walters allegedly called Donald Trump "to apologize" amid O'Donnell's public feud with him.
"Barbara and I got in a huge fight, and it was about the Donald Trump thing. He published an open letter to me in the Post," O'Donnell recalled. "In it, he wrote that she'd called him 'to apologize for my behavior.' I was like, 'Whoa.'"
"We got into an argument in the makeup room that day," she continued. "I said, 'I can't believe that I haven't heard from you during all of this time but that you've been communicating with him. Do you consider him your real friend, Barbara? I thought we had something real and something different than the way you've been treating me.'"
The TV personality said her fight with Walters "got loud and people in shock because nobody talked to her like that."
"I said something about her daughter, which I shouldn't have said. She was hurt. And we were live in 20 minutes," O'Donnell said, adding that she didn't say anything "horrible" about Walters' daughter. "Sometimes I go back and find that episode and I watch it, and I can see how tense it was. But I have apologized to her many times, and we got past it and saw each other [before her death in 2022]."
Elsewhere in the interview, O'Donnell opened up about her relationship with Ellen DeGeneres, specifically their apparent falling out.
The actress said Ellen hurt her feelings many years ago when she made a "mean" comment about her during an interview with Larry King.
"Larry King said, 'Whatever happened to Rosie O'Donnell's show? She went down the tubes as soon as she came out,'" she recalled to THR. "And the quote that Ellen said was, 'I don't know Rosie. We're not friends.' I was watching TV in bed with my wife going, 'Did she just say that?'"
O'Donnell previously spoke about Ellen's remark while appearing on "Watch What Happens Live" in September. However, she told THR that Ellen texted her after she seemingly saw her interview.
"She wrote, 'I'm really sorry and I don’t remember that.' I guess she saw me talk about it on Andy Cohen's show,'" she explained. "I remembered it so well, I had T-shirts printed and I gave them to my staff that said 'I don't know Rosie. We're not friends.' I have a picture of her holding [my then-infant son] Parker. I know her mother. I could identify her brother without her in the room. I knew her for so many years. It just felt like I don't trust this person to be in my world."
O'Donnell went on to share why she never appeared on "The Ellen DeGeneres Show."
"She used the same staff from my show -- Jim Paratore, Andy Lassner. So that was odd. It was very similar to my show," she told THR. "And then I asked to go on because of something I was promoting, and she said no. And I remember going, 'Seriously?' After she said no that one time, whenever they would ask [me to appear] on the show, I would say no."