As a young boy, Guilherme Paraense moved from his birthplace of Belém to Rio de Janeiro. He attended the Military School of Realengo, where he started practicing shooting and soon was discovered as a great talent. In 1914 in the rank of a lieutenant, he was one of the founders of the Revolver Club, in order to foster the sport of shooting. In the late 1910s, Paraense became Brazilian champion and, in 1922, South American champion in revolver shooting. Based on his solid results, Paraense was invited to join the Brazilian team for the 1920 Olympics. With his victory in the military pistol event, he was the first Brazilian gold medal winner. He later took part in the 1930 Brazilian Revolution, bringing the authoritarian president Gétulio Vargas to power. In 1952, Paraense left the Army as a lieutenant-colonel. Paraense died from a heart attack. The shooting range of the Military Academy of Agulhas Negras and an annual tournament are named in his honor.