The "Formation" singer and Carey posed together while attending a benefit for the HeartView Global Foundation at the Skirball Cultural Center. "Two girls, one cause," newly engaged Carey captioned an Instagram photo of the pair.
Queen Bey slayed in a cleavage-baring white cape dress for the event. She wore minimal makeup and kept her tousled chestnut locks in a messy updo.
The "We Belong Together" songstress, meanwhile, rocked a low-cut sparkly dress. She also wore her gorgeous 35-carat engagement ring. (The star's billionaire boyfriend, James Packer, popped the question last month.)
Beyoncé and Carey have been pals for years. In March 2014, Beyoncé gushed over Carey while wishing her a happy birthday. She posted a photo on her website, which Carey then reposted on Facebook.
"Happy Birthday Mariah!" the photo read. "May you continue to bless the world with your incredible voice!"
Carey replied: "Thank you Beyonce, even though I don't have birthdays, only anniversaries (lol!), still you're always so generous! Your talent is massive as the beauty of your heart."
Sign up now for the Us Weekly newsletter to get breaking celebrity news, hot pics and more delivered straight to your inbox!