Describing Rooney as a "wonderful woman," O'Donnell reveals the pair have been in a long-distance relationship since going public in November 2017.
The former "The View" co-host confirmed the news at the 15th anniversary celebration of her organization -- Rosie's Theater Kids -- in New York City Monday night, telling PEOPLE that their 23-year age gap often confuses fans, who mistake Rooney for O'Donnell's 20-year-old daughter, Chelsea, who's pregnant with her first child.
"A lot of people say, 'Oh, my god -- Chelsea looks so great!' I'm like, 'That's not Chelsea. That's my soon-to-be spouse,'" O'Donnell told the publication as Rooney stood by her side. "It's a little tricky. In the airport, people say, 'Rosie, can I have a picture of you and your daughter?' [Elizabeth] doesn't seem to think it's an issue at all. Nobody ever does, but I do sometimes."
"I keep telling her I'm too old for her, but she doesn't seem to care," O'Donnell joked. "She's like, 'I was in the Army! I put my life on the line every day. You think I don't know who I want to date?' I'm like, 'Alright, I guess that's true.' She has a lot of good points."
Describing her 33-year-old fiancée as a "wonderful woman," O'Donnell revealed that the pair have been in a long-distance relationship since going public in November 2017.
"She lives in Boston now, and I live here in New York, [so] it's been a long-distance thing," said O'Donnell, who also bragged about Rooney being an undefeated boxer during her time of service.
"She's very much an equal," O'Donnell added. "She's very much her own person and loves what she does. She's a pretty unbelievable young woman."
As for their big day, O'Donnell said she and Rooney decided it would be "best" to tie the knot "a long time in the future."
After confirming the news, Rooney revealed the first shot of her stunning engagement ring on Instagram:
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