Omar Niño Romero (born 12 May 1976) is a Mexican former professional boxer who competed from 1995 to 2016.
Known as "Giant Killer", he is the former WBC Light Flyweight Champion, defeating Brian Viloria in a major upset in August 2006 for the title.
In his next fight, Niño Romero fought Viloria in a rematch to a majority draw decision and a retention of his title on November 18, 2006 in Las Vegas, Nevada.
The win was marred with controversy, as Niño allegedly tested positive for methamphetamine in his post-fight urinalysis following the bout with Viloria.
[3] He fought Rodel Mayol on February 27, 2010, in Mayol's first defense of the WBC light flyweight title at the Coliseo Olimpico de la UG in Guadalajara, Jalisco, Mexico.