Robert Downey Jr. celebrated his 50th birthday [1] with a star-studded bash in Santa Monica on Saturday. Robert and his wife, Susan, and a group of A-list friends gathered at the historic Barker Hangar to enjoy cocktails and live music, including a performance by Duran Duran, in the actor's honor. Gwyneth Paltrow arrived with her rumored boyfriend [2], Glee producer Brad Falchuk, while Reese Witherspoon [3] and her husband and Gwen Stefani [4] and Gavin Rossdale [5] were also in attendance. Orlando Bloom [6], Jason Bateman [7], and Justin Theroux were seen greeting each other outside, while Jennifer Aniston [8] came with a gift bag in hand. Katie Holmes also made an appearance [9], as did Jeremy Renner, Tobey Maguire [10] and his wife, Jennifer, and Jack Osbourne and his pregnant wife, Lisa. RDJ later took to Facebook [11] to share his gratitude, writing, "Dear Mother Nature, Thank you for 50 years of loving tolerance..." The guest list included many of the same stars who attended Robert's wife Susan's 40th birthday celebration [12] in the San Francisco Bay Area in November 2013.

Robert Downey Jr. and His Wife, Susan

Jim Toth, Reese Witherspoon, Jack Osbourne, and Lisa Stelly

Brad Falchuk and Gwyneth Paltrow

Justin Theroux, Orlando Bloom, and Jason Bateman

Tobey Maguire and Jennifer Meyer

Jennifer Aniston, Justin Theroux, and Orlando Bloom

Gwyneth Paltrow and Brad Falchuk

Gwen Stefani and Gavin Rossdale

Katie Holmes