Miss Guatemala, Laura Godoy, was chosen Miss Congeniality after the two-hour pageant that featured live performances by US pop group Train and Nigerian-born Australian singer and dancer Timomatic.
Contestants must be aged between 18 and 27, unmarried and with no children.
The contest was broadcast live on US television from the Planet Hollywood hotel and casino in Las Vegas and seen by an estimated 1 billion viewers on TV and online in 190 countries, organizers said.
Culpo will travel the world for the next year representing the Miss Universe Organization and a charity of her choice.
After reaching the top five, Culpo was asked to name one thing she would never do again. "Picking on my siblings growing up," she replied.
The contest, owned jointly by businessman Donald Trump and the NBC network, held a moment of silence for the 20 children and six staff gunned down at an elementary school in Newtown, Connecticut, on December 14.
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Miss Universe in Las Vegas | Delia Monica Duca crowns Miss Universe Romania contest |