Simon Newcomb Wilson, 64, a retired official in the Latin American bureau of the State Department, died of cancer Friday at Washington Hospital Center.

He had retired last year after 33 years with the State Department. He specialized in the Organization of American States and related agencies.

Mr. Wilson had participated in all of the major inter-American conferences on the structure and role of the OAS, including the one at Bogota, Colombia, in 1948 that was interrupted by rioting after an assassination.

He had received two State Department superior honor awards and a certificate of recognition from the Inter-American Institute of Agricultural Sciences.

Mr. Wilson was born in Oslo, Norway, the son of American parents. He was educated in Switzerland and New York City. He graduated from Antioch College and received a master's degree in international relations from the Fletcher School of Law and Diplomacy.

During World War II, he served with the Navy and was stationed for two years near Bahia, Brazil.

He is survived by a son, Allan, of the home in Chevy Chase; a daughter, Judith, of San Francisco, and three sisters, Mary H. Wilson, of Washington, Herta W. Cavenaugh, of Baltimore, and Mildred W. Noce, of Washington, Va.

The family suggests that expressions of sympathy be in the form of contributions to the American Cancer Society.