Miss Universe 1963 was the 12th Miss Universe pageant, held at the Miami Beach Auditorium in Miami Beach, Florida, on 20 July 1963.

At the end of the event, Norma Nolan of Argentina crowned Iêda Maria Vargas of Brazil as Miss Universe 1963. It is the first victory of Brazil in the history of the pageant.

Contestants from fifty countries and territories competed in this edition. The pageant was hosted by John Charles Daly, while Arlene Francis and Gene Rayburn served as backstage correspondents.

Contestants from fifty countries and territories were selected to compete in the pageant. Two candidates were appointed to represent their countries after being a runner-up at their respective national pageants, while one candidate was appointed to represent her country to replace the original dethroned winner.

Maureen Thomas, first runner-up of Miss Wales 1963, was appointed to represent Wales because Miss Wales 1963 Pat Finch was not "Welsh enough" according to pageant organizers. Miss Turkey 1963, Gülseren Esen Kocaman, did not participate for unknown reasons, she was replaced by Miss Turkey 1961, Güler Samuray.

This edition saw the debuts of The Bahamas, Curaçao, Okinawa, and Trinidad and Tobago, and the returns of Nicaragua, which last competed in 1955; the British Guiana in 1958; Suriname in 1960; and Denmark and Suriname last competed in 1961.

Francine Marcos of Dahomey withdrew after arriving late to the competition. Susan Pratt of England on the other hand, withdrew after being involved in a car accident which left her with a broken leg.

Nik Azizah Yahya of Malaya withdrew after not reaching the minimum age requirement. Yen-Ping Cheung of Hong Kong, Mona Slim of Lebanon, Maria Penedo of Portugal, and Noela Bernardino of Tahiti withdrew for undisclosed reasons. Haiti, the Republic of China, Singapore, and the United States Virgin Islands withdrew after their respective organizations failed to hold a national competition or appoint a delegate.