Stepping out for a birthday BBQ, Jennifer Aniston was one of the many celebrity guests dropping by Sacha Baron Cohen’s Hollywood Hills estate on Sunday afternoon (October 19).

Sacha and Isla Fisher threw the shindig in celebration of their daughter Olive's all-important first birthday.

Also in attendance were Jen’s "Friends" co-star/BFF Courteney Cox, talk show host Ellen Degeneres, who attended with her wife Portia de Rossi, as well as the always-hilarious Ben Stiller.

Meanwhile, Miss Aniston was surprisingly without musician John Mayer, as the two spent the entire past week heading out on multiple dinner dates - starting rumors of a rekindled romance.

Gossip Girls

Enjoy the pictures of Jennifer Aniston and friends at the BBQ party (October 19).