Waldo Ariel Kantor (born 11 January 1960) is a retired volleyball player from Argentina, who represented his native country at the 1984 Summer Olympics in Los Angeles, California and the 1988 Summer Olympics in Seoul.

In Seoul, Kantor won the bronze medal with the men's national team.

With Ferro Carril Oeste, Kantor won the Morgan Cup of 1979, and the national championships of 1980 and 1981.

After retirement, Kantor became a successful coach with Argentine first division Bolivar Buenos Aires, winning the 2007–08 championship.

He also played at Mendele from Loma Hermosa, where he defeated different teams from the area, such as Villa Piagio, Los Matreros, and River.