Amateur Highlights

• 1995 National Junior Olympics Gold Medalist at 100 lbs.
• 1996 National Junior Olympics Gold Medalist at 106 lbs.
• 1996 World Junior Olympics Gold Medalist at 106 lbs.
• 1997 National Junior Olympics Bronze Medalist at 112 lbs.
• 1998 National Amateur Championships Bronze Medalist at 106 lbs.
• 1999 National Amateur Championships Gold Medalist at 106 lbs.
• 1999 National Golden Gloves Light Flyweight Gold Medalist
• 1999 World Amateur Championships Gold Medalist
• 1999 USA Boxer of The Year
• Member of the 2000 US Olympic Team. His results were:
  • Defeated Sergey Kazakov (Russia) 8-6
  • Lost to Brahim Asloum (France) 4-6

Flyweight

Viloria started his professional career as a flyweight and picked up 17 wins with no defeats. He also captured and defended the NABF Flyweight title in the process before moving down to the Light Flyweight division.

Light Flyweight

On September 10, 2005, Viloria dropped down to light flyweight and won the WBC crown by knocking out Eric Ortiz in the first round with a powerful right.

He successfully defended it once on February 18, 2006, against José Antonio Aguirre (boxer) and was undefeated in 20 bouts. Viloria's unbeaten streak ended when he was dethroned by Mexican Omar Niño Romero on August 10, 2006.

In a rematch held on November 18, 2006, at Las Vegas, Romero held on to his title with a controversial majority draw decision, with Viloria knocking down Romero twice during the fight. Romero was then stripped of his title after failing a post fight drug test for methamphetamine and the decision was overturned into a no-contest.

On April 14, 2007, he fought Edgar Sosa for the vacant WBC Light Flyweight title but lost via majority decision.

Super Flyweight

Viloria then decided to move up to the super flyweight division and began training under former champion, Robert Garcia, at La Colonia Gym in Oxnard, California.^[2]

Brian Viloria won via unanimous decision against Jose Garcia Bernal (26-11-1) in his debut at the super flyweight division at the Alameda Swap Meet in Los Angeles, California on January 5, 2008.^[3] Viloria secured four more victories before deciding to move back down to Light Flyweight.^[4]

Return to Light Flyweight

On April 19, 2009, Viloria moved back down to junior flyweight to challenge Mexican Ulises "Archie" Solís for the IBF Junior Flyweight title. Pressured by a fading career due to his past losses in big fights, Viloria defeated Solis, whom at the time of the fight was rated the #1 Jr. Flyweight by The Ring^[5] in the 11th round with a vicious right to the jaw. The official bout stoppage was a KO 2:56 into the 11th round.^[6] The fight was held at Araneta Coliseum in the Philippines, site of the Thrilla in Manila, as the co-main event of the Donaire-Martinez fight. Viloria snapped Solis' 11-fight unbeaten streak, 8 of which were title defenses while extending his win streak to 6.

Viloria successfully defended his IBF Junior Flyweight title on August 29, 2009, against Jesus Iribe.^[7]

For his second defense, Viloria fought Carlos Tamara of Colombia on January 23, 2010. Though leading in points, the referee called a halt to the bout in Tamara's favor as Viloria was close to passing out in the twelfth round awarding Tamara a TKO victory and the belt.^[8] Moments following the bout, Viloria passed out due to extreme exhaustion.^[9]

Return to Flyweight

Viloria returned to the flyweight division against Mexico's Omar Soto on July 10, 2010, at the Yñares Sports Arena, Pasig, Metro Manila.^[10]

On July 16, 2011, Viloria captured the WBO Flyweight title by besting Mexican Julio César Miranda.^[11] On December 10, 2011, Viloria stopped Giovani Segura by way of an 8th Round TKO.^[12] On May 13, 2012, Viloria stopped his rival Omar Niño Romero in the 9th round for another successful defense of his WBO Flyweight title.^[13]

On November 17, 2012, Viloria challenged Hernan Marquez in a flyweight unification between his WBO title and the Marquez's WBA crown. He went on to stop Marquez in 10 rounds becoming the first flyweight unified world champion since 1965.^[14] Viloria then lost both titles to Juan Francisco Estrada on April 6, 2013.^[15]

Viloria picked up four more wins before facing pound for pound king Román González on October 17, 2015, for the WBC and The Ring Flyweight titles. Viloria was stopped in the 9th round and lost via TKO. At the time of the stoppage, the scorecards were 78-73, 78-73 and 79-72 in favor of Gonzalez.^[16]

Viloria, ranked #2 by the WBA, later fought Artem Dalakian, who was ranked #1 by the WBA, on February 24, 2018, for the WBA flyweight title but lost by unanimous decision. He implicitly retired after the fight.^[17][18]