Miss Philippines, Janine Tugonon, was the pageant's runner-up, while Miss Venezuela, Irene Sofia Esser Quintero, came in third.
Culpo, 20, is from Rhode Island. She is the first American to win the Miss Universe crown since Brook Lee in 1997.
This year's 2-hour pageant aired on NBC, with Andy Cohen and Giuliana Rancic serving as co-hosts.
Celebrity Couples of 2014 [PHOTOS]