Hermes Franca-Barros (born August 26, 1974), known as Hermes Franca , is a Brazilian mixed martial artist currently fighting at Lightweight for the Ultimate Fighting Championship.

Franca made his UFC debut at UFC 42, defeating Richard Crunkilton by unanimous decision. He went on to win his next UFC fight against Caol Uno (who narrowly missed the lightweight championship after drawing with B.J. Penn) at UFC 44 before losing a majority decision to Josh Thomson at UFC 46.

His next outing in the UFC, against Yves Edwards, was unsuccessful, losing the fight by split decision. Edwards would once again beat Franca by split decision in their encounter at Euphoria: USA vs. World in 2005, starting what would be a very bad year - marked with three straight losses - for the Brazilian fighter.

However, 2006 would prove to be a much better year for Franca. In March, he toppled WEC champion Gabe Ruediger to capture the WEC Lightweight championship, and then knocked out Team Quest fighter Ryan Schultz to take the AFC Lightweight championship in April.

Franca would continue his winning streak against the likes of Toby Imada and Brandon Olsen before signing a contract to fight Roger Huerta at UFC 61 in July. Although Franca's opponent was changed - Huerta pulled out due to injury, with UFC newcomer Joe Jordan taking his place - Franca still reigned successful in his UFC return, stopping Jordan by triangle choke submission in the third round.

On August 4, 2006, it was revealed that Franca had accepted a late-notice fight with Jamie Varner at UFC 62. Franca comes in as a late replacement for Spencer Fisher, who injured his back while preparing for the fight. Despite accepting the fight on short notice, Franca reigned victorious, catching Varner in an armbar submission in the third round.

Franca successfully defended his WEC Lightweight championship against Nathan Diaz, brother of UFC veteran Nick Diaz, at WEC 24 on October 12, extending Franca's win streak in 2006 to seven consecutive victories.

Franca won his fight against Spencer Fisher at UFC Fight Night 8 by TKO in the second round; after his victory he got down on his knees (à la Georges St. Pierre) and begged UFC President Dana White to grant him a title shot against Sean Sherk. During the post-fight press conference White confirmed that Franca would be given a title shot at UFC 73[2]. Franca lost to Sean Sherk by unanimous decision. On July 19, 2007 the California State Athletic Commission announced Franca had tested positive for the banned steroid Drostanolone in a post-fight drug test following his championship fight at UFC 73. He had been suspended from competing in California until July 5, 2008 and had been fined $2,500.[3]

He has since left The Armory and has been removed from their main site as an instructor.

Hermes spent early January 2008 helping BJ Penn train for his 5-round fight against Joe Stevenson for the vacant UFC lightweight championship at UFC 80.

Franca lost his first fight in the UFC (since his suspension in 2007) on July 19, 2008 to Frankie Edgar via unanimous decision.

He then went on to defeat Marcus Aurelio via unanimous decision at UFC 90 on October 25th, 2008.

Franca was scheduled to fight Joe Lauzon on February 7 in the main event for UFC Fight Night 17. But Franca pulled out of the event with a torn anterior crucial ligament in his right knee.