Ellen Pompeo, Gwen Stefani & Jessica Alba: Harlow Madden Birthday Party!

It was a star-studded third birthday party for Nicole Richie and Joel Madden‘s daughter Harlow at the Tree House Social Club on Saturday (January 8) in Beverly Hills, Calif.

Ellen Pompeo and husband Chris Ivery took their adorable 15-month-old daughter Stella Luna, who looked positively adorable in a pair of shades and oversized beanie.

Gwen Stefani and husband Gavin Rossdale brought along their fashionable sons Kingston, 4, and Zuma, 2.

Jessica Alba and husband Cash Warren were spotted at the party with their daughter Honor, 2.

Tobey Maguire‘s wife Jennifer Meyer hit up the party with daughter Ruby, 4, and son Otis, 20 months.

Kourtney Kardashian left baby daddy Scott Disick home but brought Mason to the festivities.

Also pictured here: Nicole and Joel leaving the party with their son Sparrow, 15 months. And FYI, Harlow‘s actual birthday is on Tuesday (January 11).

20+ pictures inside of Harlow Madden‘s third birthday party…