Originally a bus driver,[5] Glenn Donaire compiled a 52-8 amateur record and earning various local and regional titles,[6] made it to the semi-finals of the US Olympic Trials in 2000 and lost a highly disputed decision to former world champion Brian Viloria.

Glenn is very proud to be a Filipino boxer and has worn the Philippine flag on his trunks his entire career.

May 5, 2006, Glenn won the NABO and NABA flyweight titles by defeating Cesar Lopez by a 12 round decision.

The fight was stopped in the 4th round due to a broken/locked jaw suffered by Donaire from an alleged elbow attack.

Subsequently, Donaire moved up a weight class and defeated Omar Salado in Mexico City[8] to win the vacant WBC Latino super flyweight title by unanimous decision on March 16, 2012.