Freddy Castillo (born June 15, 1955 in Mérida, Yucatán) is a Mexican former world boxing champion.
Known as "Chato Loco", Castillo turned pro in 1971 and won the WBC light flyweight title with a TKO win over Luis Estaba in 1978. He lost the belt in his first defense later that year to Netrnoi Sor Vorasingh by split decision. He later moved up in weight and in 1982 won the WBC and The Ring flyweight titles with a decision win over Prudencio Cardona. He lost the belts in his first defense to Eleoncio Mercedes by split decision. He retired in 1986 after losing to Sot Chitalada for the WBC flyweight title.
| Preceded by Luis Estaba |
WBC Light Flyweight Champion 1978 Feb 19 – 1978 May 6 |
Succeeded by Netrnoi Sor Vorasingh |
| Preceded by Prudencio Cardona |
WBC Flyweight Champion The Ring Flyweight Champion 1982 Jul 24 – 1982 Nov 6 |
Succeeded by Eleoncio Mercedes |