"She was special to me, very special," the comedian and actor, 58, explained on SiriusXM's "The Howard Stern Show" on Tuesday. "I think she's lovely."
He also called her the "great love of my life" in the new semi-autobiographical novel "Memoirs and Misinformation" he wrote with Dana Vachon, which was published July 7.
The actors started working together while filming "Me, Myself and Irene" in 1999 and began dating after the film finished shooting. They quickly became engaged and attended the 2000 Golden Globes together — but everything came to an end late that year.
Carrey was married from 1987 to 1995 to Melissa Wormer, with whom he had a daughter, Jane; and to actress Lauren Holly from 1996 to 1997. Zellweger married singer Kenny Chesney in 2005, but it was annulled in 2006. Neither is currently married.
Though their time together was brief, there was real interest from the paparazzi and tabloid media in their relationship; in 2000, Carrey told Entertainment Weekly he felt something "chemical" for Zellweger while making the movie.
"It was a very unexpected, wonderful thing," Zellweger told EW in 2000. "We didn't see each other for a few months after we finished the picture — or really speak even — and I just noticed his absence significantly. It just felt like, 'Wow, I really miss him.'"
Still, despite the fact that he cares for Zellweger, he's not holding a candle for her.
"I don't regret — I don't have those things," he continued. "But I do appreciate the people that have come through my life for the good that they gave me … but I don't pine for anybody, it's not that kind of situation. It's just my way of saying, 'There was a very important thing there,' and to recognize that."