Ninety-two women from around the globe participated setting the record for most contestants ever to compete in the competition.
Nel-Peters is the second South African beauty queen to win the Miss Universe crown after Margaret Gardiner in 1978.
Along with the title, Nel-Peters earned a yearlong salary, a luxury apartment in New York City for the duration of her reign and more prizes.
"If women take hands and stand together, we are unbreakable", Nel-Peters said.
Pageant fans around the world became the seventh judge of the 2017 Miss Universe pageant as they cast votes during the selection of Top 16 semi-finalists, and Swimsuit and Evening Gown competitions. She also works with deaf students and is involved in the development of a new sign language app.
This year's edition of the Miss Universe pageant has separated contestants by geographic region for the first time.
Miss Colombia, Laura González was the first runner-up, while Miss Jamaica, Davina Bennett was the second.
U.S. gymnastics doctor Larry Nassar pleads guilty to sex charges
Nassar's accusers previous year . "I'm still processing it, I have mixed emotions", Larissa Boyce said. The school's gymnastics coach, Kathie Klages, was suspended and stepped down past year .
Nel-Peters is an advocate of women's rights.
For TV host Bianca Gonzalez, the 26-year-old beauty from Camarines Sur is still the Filipinos' Miss Universe.
Harvey, a five-time Emmy Award victor, mentioned the moment from when he announced the wrong victor at 2015 Miss Universe.
Others in the top 10 besides the eventual victor were Miss Thailand, Miss Spain, Miss Colombia, Miss Brazil, Miss Canada, Miss Philippines, Miss Venezuela and Miss Jamaica.
More than 90 women from around the world are set to take the stage in the Miss Universe pageant.
"I think that it's really important that we continue to show diversity of all sizes, ethnicities, backgrounds and religion", she said.
Seated on the judges tables were Miss Universe 2015 Pia Wurtzbach, Hollywood Today host Ross Mathews, fashion correspondent Jay Manuel, top internet influencer Lele Pons, UFC backstage reporter Megan Olivi, hair care/spa products company founder Farouk Shami, and Miss Universe 1998 Wendy Fitzwilliam.