The couple became engaged over the weekend in New York after dating for a year, Us Weekly magazine reported Tuesday. O'Connell's publicist, Joy Fehily, confirmed those details to The Associated Press.
"We couldn't be happier and are looking forward to the next chapter of our lives," the couple said in a joint statement.
No other details were available.
Romijn, 32, was married to John Stamos (search) (television's "Full House") for six years. They announced their split in April of last year and their divorce was finalized in March. She has since dropped Stamos from her last name.
Earlier this year, Romijn finished filming "Man About Town," which features O'Connell. They also worked together on "The Alibi," which hasn't been released.
The 31-year-old O'Connell, whose films include "Stand by Me," "Jerry Maguire," "Tomcats" and "Mission to Mars," stars in the NBC medical crime drama, "Crossing Jordan."