Carlina Duran, recently named Miss Dominican Republic, has been stripped of her title.
Organisers have confirmed Carlina will have to pass on the crown to the runner-up, 24-year-old Dulcita Lieggi, after discovering she was previously married.
The rules state that those vying for the crown must be single. But Magaly Febles, director of the Miss Domincan Republic contest, said Carlina wed in 2009.
Ms Febles told the Dominican television news programme Noticias SIN that Mrs Duran acknowledged she was married.
In a statement Mrs Duran said she had never lived with her husband.
"In my daily life, I remained like a single woman, without thinking of myself neither materially nor spiritually married," it read.
The statement also said the marriage was brief and the couple had begun annulment proceedings.
Mrs Duran called her decision to hide her marriage from the contest organisers the "fruit of my inexperience".