Rosie O'Donnell has named her "worst" talk show guest.

The comedian revealed which celebrity had been the hardest to interview, during an appearance on Australian late-night show, Sam Pang Tonight.

"One of the worst, who, I love the guy, but he's not good on talk shows: Keanu Reeves," Rosie, 63, declared, adding she had no intention to throw the 61-year-old star "under the bus" with her frank description of trying to interview him.

"He's so sweet, he looks gorgeous, I love all his movies, but he would not answer a question," the former host of The Rosie O'Donnell Show continued. "I'd say, 'So, Keanu, how's it going, how are you feeling?' (He'd reply) 'Good.'"

Rosie went on to explain that because her TV show was aired live, she had no way of editing the interview to make it seem more entertaining.

"We were live. We couldn't retape," she recalled. "I finally said after three minutes, 'You know, Keanu, it is a talk show. You have to talk!'"

She added the John Wick actor was "a lovely man and a good-hearted guy" and that he had later made a better impression once he learned some media skills.

"But he did come back, and he got the hang of it," Rosie said.