It's the second year running a Miss Venezuela has won the global beauty pageant - Dayana Mendoza was last year's victor.
Fernandez beat 50 other competitors to win the contest. Miss Dominican Republic Ada Aimee de la Cruz was named first runner-up and beauties from Kosovo, Australia and Puerto Rico were also named among the runners-up.
Venezuela has produced five previous Miss Universe winners in 1979, 1981, 1986, 1996 and 2008.
Flo Rida, Heidi Montag, David Guetta and Kelly Rowland performed at the pageant.