Cantrell rode an opera performance to the title in Atlantic City's Boardwalk Hall Sunday night, besting 51 other competitors in the nationally televised pageant.
PHOTOS: 2015 Miss America Pageant
The pageant also marked the return of Miss America 1984 Vanessa Williams, who was back for the first time after resigning the crown following a nude photo scandal. Pageant executive chairman Sam Haskell apologized to Williams on behalf of the pageant.
"I want to apologize for anything that was said or done," Haskell told Williams as they stood on the stage. "Vanessa: Welcome back!"
For Williams, who went on to stardom on television and on the Broadway stage, it was a triumphant return to the Miss America stage.
"I did the best I could in my reign as Miss America," she said during Sunday's pageant.
Cantrell sang an opera number for her talent performance.
She won a preliminary competition earlier in the week, also with an opera performance.
Miss Georgia's win ended New York's dominance at the Miss America pageant. Last year's Miss America, Kira Kazantsev, was the third consecutive Miss New York to win the title.
"I can't believe it's been a year since I was backstage getting ready to compete, just as the contestants are right now," Kazantsev said at a press conference Tuesday afternoon in Boardwalk Hall. "
Preliminary competition in talent, interviews, evening wear and swimsuit competition ran through Thursday.
On Saturday, the Miss America contestants hit the Atlantic City Boardwalk for the annual "Show Us Your Shoes" parade.
Most of the shoes had designs specific to the contestant's home states. New Jersey, for instance, had dice and Monopoly money on her shoes in a nod to the pageant's Atlantic City history. Miss Idaho had a potato.
Contestants from all 50 states, the District of Columbia and Puerto Rico were vying for the crown. The U.S. Virgin islands, which competed last year, could not field the required minimum number of entrants this year, pageant officials said. It is eligible for future competitions.