Joel Madden Harlow Madden Nicole Richie father daughter baseball cap

A day of father and daughter bonding!

While Nicole Richie was busy working on her fitness at the gym, dad Joel Madden took daughter Harlow (who turned three last month) to a birthday party yesterday with some of Hollywood's elite!

Also attending the b-day gathering? Gwen Stefani and her boys, as well as Kourtney Kardashian and son Mason. Just another day in the life... of a celebrity, that is.