Leopoldo Cantancio was a boxer who competed at the 1984 Summer Olympics and 1988 Summer Olympics. He was just 18 years old when he won a bronze medal in the bantamweight division at the 1981 Southeast Asian Games in Manila. At the age of 21, he participated in his first Olympic Games in 1984. In the round of 16, he absorbed a 2-3 loss to Nigeria’s Christopher Ossai but the jury reversed the verdict and handed him a 5-0 win and a quarterfinal date with South Korean Chun Chil-sung where Cantancio lost. He represented the country again at the 1988 Summer Olympics but could not duplicate his quarterfinal finish in Los Angeles.

Cantancio won the gold medal at the 1983 Southeast Asian Games in Singapore in the featherweight division and in the Asian Amateur Boxing Championships in Naha, Japan in the same division. He also won gold at the 1985 Asian Amateur Boxing Championships in Bangkok in the lightweight division and in the 1987 Southeast Asian Games in Jakarta in the lightweight division.

Cantancio became a full-time police officer after hanging up his gloves and later.

1984 Summer Olympics, Los Angeles
1988 Summer Olympics, Seoul