Posting a cute snap of the pair laughing and chatting at the 2013 Beat the Odds Awards in Beverly Hills, California, the 41-year-old Big Little Lies star paid tribute, to the qualities that make Garner a great friend.
"Here's lookin' at you, Jen!" the actress wrote. "Happy Birthday to my gorgeous friend #JenniferGarner who always laughs at my jokes and my bad dance moves! Love you!"
On Sunday, Witherspoon was spotted celebrating Garner’s birthday with a group of friends at members-only Malibu hot spot The Little Beach House.