Michelle Williams and Jason Segel
Lionel Hahn/Abaca; Katy Winn/AP
03/30/2012 at 03:00 AM EDT
has new romance in her life: the actress is dating How I Met Your Mother
's Jason Segel
"It's been a few months," says a friend of the Oscar-nominated actress
, who confirms the new relationship to PEOPLE. "I've never seen her happier."
In recent weeks, the two have been spotted out together in Brooklyn, where Williams lives, and also in Los Angeles, where they enjoyed dinner at Comme Ça on March 16.
Most recently, Segel, 32, was spotted at the Chateau Marmont on March 27 sans Williams, 31, though an onlooker tells PEOPLE he was happily chatting with his friends and telling jokes and describes him as "very laid back."
As for the connection, a source tells PEOPLE the pair met through Williams's best pal – and Segel's former Freaks and Geeks
costar – Busy Philipps
And in a cryptic Tweet (that was since taken down) posted March 5, the actor wrote, "If I fell in love would you guys be happy?"
In a recent interview with Parade
, the Jeff, Who Lives at Home
actor opened up about what he's looking for romantically, saying, "I don't want to have a girlfriend for the sake of having a girlfriend. I have no desire to pick a random girl. I want the right girl. There are plenty of opportunities, but I would rather have the right one."
Williams has a daughter, Matilda
, 6, from her relationship with Heath Ledger
Reporting by JENNIFER GARCIA