Horacio Accavallo (b. October 14, 1934) was an Argentine flyweight boxer who fought from 1956 until 1967. He retired with a record of 75 wins (34 KOs), 2 losses and 6 draws.

Accavallo fought mainly in Argentina, where the tenacious southpaw was virtually unbeatable. On March 1, 1966 he won the WBA world flyweight championship by outpointing Katsuyoshi Takayama on a 15 round split decision in Tokyo, Japan. Accavallo had been the number one contender for the title held by Salvatore Burruni, but Burruni chose to defend the title against someone other than Accavallo. Since the WBA had mandated that Burruni fight Accavallo, it stripped the champion of his crown and sanctioned the Accavallo-Takayama match for its version of the title.

Accavallo retired as the reigning WBA champion after escaping with a controversial 15 round split decision victory over former world flyweight champion Hiroyuki Ebihara .