By Caitlin Petreycik
Jun 08, 2012 @ 12:15 pm
Splash News (2); TheGreenTeam / Splash; AKM-GSI

Today is World Oceans Day, and to mark this global celebration of ocean conservation, we’ve rounded up snapshots of our favorite stars working their  hottest bikinis at the beach. See what Scarlett Johansson, Rihanna, Julia Roberts, Leighton Meester, and more celebs wear to soak up those sunny rays in the gallery.

MORE: • Our 50 Favorite Bikinis • The Hottest Beach Couples!Where to Buy Rihanna's Bikini