The 31-year-old actress - who ended her relationship with NHL star Brad Richards in January after two months of dating - has reportedly embarked upon a new romance with the actor and the couple are said to be ''extremely happy''.
Joel took Olivia to the second season premiere of 'The Killing' in Los Angeles last night (26.03.12) and friends claim the new relationship is ''heading towards being serious''.
An insider told E! News: ''They have been together for about three months. They met last year, but they didn't get together until just before Christmas.
''He is a super-normal guy and she is a really down-to-earth girl and they just get each other. They are on the same wavelength intellectually, and they have the same sense of humor. It's been going on for a little while and it's heading towards being serious. They are extremely happy together.''
Olivia - who briefly dated Justin Timberlake and has been romantically linked with Matthew Morrison in the past - recently admitted she has secretly had a number of famous boyfriends, which she has managed to keep under wraps by going on dates to unpopular destinations.
The 'Date Night' star explained: ''Over the last year, I've dated guys that, if people knew, would be on the cover of magazines. But they don't find out because I say, 'Hey, would you like to go to Valencia?'
''Some people go to restaurants that are so popular. They say it's really good food. You're like, 'What food is worth that?' The lobster ceviche will be just as good in a to-go box.''