Miss Universe Organization president Paula Shugart and Miss Universe 2017 Demi-Leigh Nel-Peters were present at the press conference in Bangkok.
Former Miss Universe 1965 Apasra Hongsakula and Miss Universe 2005 Natalie Glebova were also present during the announcement.
The pageant is reportedly scheduled on December 17.
Thailand hosted the pageant twice – in 1992 and 2005. The country has also produced two winners – Apasra Hongsakula in 1965 and Porntip Nakhirunkanok (Bui Simon) in 1988.