Eastwood -- whose actual birthday was on March 21 -- rocked sunglasses and a white suit that was very Miami Vice. He appeared to be the life of the '70s-themed party, as evidenced by photos snapped inside the soiree.
But he wasn't the only that went all out on his costume -- just check out these bright-hued babes!
Even his mother, Jacelyn Reeves, came ready to party.
Eastwood's sisters, Morgan and Francesca, were there, too, as well as a number of his friends, including Geoff Stults. The Zoo actor sported one of the clear standout costumes of the night -- neon sunglasses, a mesh crop top and zebra-print leggings.
The birthday boy was also joined by actresses Charlotte McKinney and Nina Dobrev, surfers Rob Machado and Taylor Knox, and fitness model Lauren Hutton, who rocked an all-white curve-hugging jumpsuit.
Hutton later took to Instagram to share a short clip of Eastwood blowing out the candles on his peace sign-covered cake.
Inside the party, guests dined on tacos and sipped on Ketel One cocktails, like the Ketel One Vodka Ultimate Martini and the Ketel One Vodka Dutch Mule. That might explain this epic photo of Eastwood playing homage to his Longest Ride character on a mechanical bull!
Oh, and did we mention the décor included cardboard cutouts of Eastwood?