Omar Andrés Narváez (; born 7 October 1975) is an Argentine professional boxer. He is a two-weight world champion, having held the WBO flyweight title from 2002 to 2010, and the WBO junior bantamweight title from 2010 to 2014. Together with Julio César Chávez, Narváez holds the world record for the most successful defenses of world titles, at 27. He is the longest reigning flyweight champion in history.
As an amateur, Narváez represented Argentina at the 2000 Olympics, reaching the round of 16 of the super flyweight bracket.
He won the WBO world flyweight title on July 13, 2002 by a unanimous decision win over Adonis Rivas. He defended the title against 15 different contenders such as Luis Alberto Lazarate, Andrea Sarritzu, Everardo Morales, Alexander Mahmutov, Reginaldo Martins Carvalho, Bernard Inom, Rexon Flores, Walberto Ramos, Brahim Asloum, Marlon Marquez, Carlos Tamara, Iván Pozo, Alejandro "Payasito" Hernández, Rayonta Whitfield and Omar Soto.
He then moved up to Super Flyweight and won the WBO Super Flyweight title on May 15, 2010, with a unanimous points decision against Nicaraguan Everth Briceno in Buenos Aires, Argentina. That same year he won the Platinum Konex Award as the best boxer from the last decade in Argentina.
Narvaez faced Nonito Donaire on October 22, 2011, at The Theater at Madison Square Garden at Bantamweight. He lost the one-sided fight by unanimous decision, his first professional loss.
He later returned to the super flyweight division where he retained the WBO world super flyweight title eight more times, defending it against 7 other boxers before getting knocked out by Naoya Inoue in the second round on December 30, 2014. This was Narvaez first and only loss by knockout.
On 14 October 2017, Narvaez fought Nikolay Potapov who was ranked #2 by the WBO and #12 by the IBF at bantamweight. Narvaez won the fight via technical knockout in the 7th round.
On 21 April 2018, Narvaez fought Zolani Tete for the WBO bantamweight title. Tete won by unanimous decision in their 12 round contest, 120-108, 120-108 on 120-108 on the judges' scorecards.