On September 19, 2005, Romijn announced her engagement to actor Jerry O'Connell. They were married on their ranch in Southern California on July 14, 2007. On July 28, 2008, it was announced that Romijn was pregnant. Romijn and O'Connell welcomed twin daughters Dolly Rebecca Rose and Charlie Tamara Tulip on December 28, 2008. Dolly is for singer Dolly Parton's first name and Charlie is for O'Connell's brother.