Quaid, 50, has proposed to his girlfriend, Texas real estate agent Kimberly Buffington, his spokeswoman, Cara Tripicchio, said. No wedding date has been set.
The TV show "Extra" reported Wednesday the couple met in March 2003 when Quaid performed with his band, The Sharks, in Austin, Texas.
This will be Quaid's third marriage. He was married to actress P.J. Soles from 1978 to 1983 and to actress Meg Ryan (search) from 1991 to 2001. Quaid and Ryan have a 12-year-old son, Jack Henry Quaid.
"The Day After Tomorrow," which had a formidable $86 million opening this past Memorial Day weekend, features Quaid as a scientist trying to prevent the end of the world when global warming unleashes disaster.