The 45-year-old actress was seen arriving in a maroon gown, separately from her fiancé Brad Falchhuk, 47 who arrived in a white tuxedo.
The 400 strong black tie bash was attended by the who’s who of Hollywood including Cameron Diaz, who also reportedly planned the bachelorette party, as well as Reese Witherspoon, Kate Hudson, Jennifer Aniston, Julia Roberts, Liv Tyler and Demi Moore.
Gwyn’s ex-husband, Coldplay rocker Chris Martin who she has remained close to since they consciously uncoupled in 2014, wasn’t in attendance.
Gwyn and Chris famously eloped when they married in 2003, so the actress says she is treating this wedding as though it’s her first.
“I’ve never had a wedding before so even though I’m 45, I sort of feel like a 21-year-old,” she previously told People.
“It’s kind of fun to talk about with my girlfriends. They send me pictures of dresses — they’re as excited about it as I am,” she added.
No word from the actress's rep as yet, but if the pair aren’t already married, then stay tuned for a wedding in The Hamptons later this year…