Gwyneth Paltrow‘s getting married toBrad Falchukthis Saturday in the Hamptons, PEOPLE confirms — and the guest list is sure to be packed with A-list friends.

A source told PEOPLE the duo celebrated with an intimate rehearsal dinner at the estate of longtime friend Jerry Seinfeld on Friday.

Cameron Diazand her husbandBenji Maddenare set to attend, a source tells PEOPLE, as is Paltrow’sIron MancostarRobert Downey Jr.and his wife Susan.

Here’s a list of the friends we can maybe expect to see at the big event.

A-List Guests from Their Big EngagementParty

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Paltrow’s mother, actress Blythe Danner, made an appearance, as did several close friends such as Julia Roberts and her husband Danny Moder, Kate Hudson, Steven Speilberg, Reese Witherspoon andDemi Moore.

Other stars were also photographed at the luxurious bash including Liv Tyler, Chelsea Handler and Jerry and Jessica Seinfeld.

Girlfriends from the Bachelorette Party

That same month, Paltrow enjoyed abachelorette party in Cabo, Mexicowith some of her girlfriends, including Diaz and designer Stella McCartney.

“Gwyneth arrived in Cabo Wednesday with a group of girlfriends, including Stella McCartney, for her bachelorette party,” a source told PEOPLE. “She looked ecstatic. They have many fun activities planned, including pool time, spa and fun dinners.”

A Conscious Reunion?

It’s possible Paltrow’s ex-husband and Coldplay frontmanChris Martinwill attend the wedding. The two eloped in 2003 and split in 2014, but have kept a friendly relationship through the years.

The pair also shares two children, 14-year-old Apple and 12-year-old Moses. Paltrow hasn’t shied away from giving fans a glimpse of her relationship with Martin, 41.

RELATED VIDEO: Stars Come Out for Gwyneth Paltrow and Brad Falchuk’s Black Tie Engagement Party

In June, she honored bothMartin and Falchuk for Father’s Dayon Instagram with separate posts.

Paltrow called him “my brother” during an interview onThe Late Show with Stephen Colbertin January.

“He’s really like my brother, we’re very familial. It’s nice, it’s great,” Paltrow said of Martin.

The singer has since been datingFifty Shades of Greyactress Dakota Johnson.

Paltrow and Falchuk first met in 2010 when she made a guest appearance onGleeas Holly Holliday, a role for which she won an Emmy Award. The two officially started dating in the summer of 2014 andconfirmed their engagementin January inGoop Magazine‘s Sex & Love issue.

source: people.com