Mariah made sure to get a snap with the man of the hour himself, who looked dashing in a sparkly navy blue suit and matching sunglasses.
Elton smartly pointed out that Mariah was rocking a serious amount of bling to the shindig, which happened to include her massive 35-carat engagement ring. "Mariah looking glam-fabulous. She's wearing more carats than I am!" he wrote on Instagram.
The 45-year-old singer, who wore a one-shouldered black dress with a peek-a-boo pink panel in the leg slit, also sat with a fierce and fabulous-looking Kelly Osbourne.
Many more celebrities turned out for Elton's annual soiree, including tablemates Lana Del Rey and Hilary Swank. Both glistened, with Lana channeling old Hollywood glam in a pale Bulgari gown and Hilary rocking a disco ball-inspired top and black skirt.
Steven Tyler also joined the fete, posing for a photo with Elton and the British singer's husband, David Furnish.
And just before the Oscars kicked off, Elton excitedly took a pic with Boy George and Caitlyn Jenner…