János Kajdi (born December 30, 1939 in Szombathely – died April 10, 1992 in Budapest) was a boxer from Hungary who won the silver medal in the welterweight division (– 67 kg) at the 1972 Summer Olympics in Munich, West Germany. In the final he was defeated by Cuba's Emilio Correa on points (5:0).
1964 (as a lightweight)
- Defeated Gurung Ramparsad (Nepal) RSC 1 (2:52)
- Defeated Alex Odhiambo (Ugnada) 5-0
- Lost to Vellikton Barannikov (Soviet Union) RSC 2 (2:12)
1968 (as a Light welterweight)
- Lost to Jerzy Kulej (Poland) 2-3
1972 (as a welterweight)