The former talk show host and the actress dated from 1997 to 2000.
The former talk show host took to Twitter on Friday to express that "this is a sad day."
"I'm sending Anne's children, family and friends all my love," her tweet continued. The message was posted just moments before ET confirmed that Heche died after suffering from injuries sustained from a car crash last week in the Mar Vista neighborhood of Los Angeles. She was 53.
"Unfortunately, due to her accident, Anne suffered a severe anoxic brain injury and remains in a coma, in critical condition," the actress' rep said in a statement to ET on Thursday, on behalf of her family. "She is not expected to survive. It has long been her choice to donate her organs and she's being kept on life support to determine if any are viable."
DeGeneres and Heche dated from 1997 to 2000. Earlier this week, DeGeneres addressed Heche's horrific car crash. When asked by a photographer if she's spoken to Heche since her car accident, DeGeneres said, "We're not in touch with each other, so I wouldn't know."
Still, DeGeneres confirmed she wanted to send her well wishes and said on camera, "I don’t want anyone to be hurt."
Back in 2020, Heche looked back on her relationship with DeGeneres.
"Our time was a beautiful part of my life and one that I wear with honor," Heche told Mr. Warburton magazine. "I was a part of a revolution that created social change, and I could not have done that without falling in love with her."