Antônio Silva (born 14 September 1979) is a Brazilian retired professional mixed martial artist and kickboxer who formerly competed in the Heavyweight division.

[8] He also trained at the Imperial Athletics gym in Boca Raton, Florida, for his quarterfinal bout with Fedor Emelianenko in the Strikeforce World Grand Prix Heavyweight Tournament.

[9] Silva made his professional debut in the United Kingdom against Georgian fighter Tengiz Tedoradze, who would become the Cage Rage British Heavyweight Champion two fights later.

Silva followed this up with a knockout win over Lithuanian fighter Tadas Rimkevicius before making his Japanese debut for K-1 Hero's.

In his debut for the organization, he defeated longtime veteran Tom Erikson via TKO and then won his next fight by knockout.

Silva faced Eric Pele in his first and only fight with the BodogFIGHT promotion and was handed his first career loss with a controversial TKO.

He was to face Jonathan Wiezorek, but the California State Athletic Commission (CSAC) discovered a benign tumor on his pituitary gland in his pre-fight medicals and refused to license the fighter.

On 26 July 2008, Silva won the EliteXC Heavyweight Championship, with a second-round TKO win over UFC veteran Justin Eilers.

Silva later tested positive for the anabolic steroid Boldenone, and was suspended for one year and fined $2,500 by the California State Athletic Commission.

On 7 November 2009, Silva suffered the second loss of his career, losing a unanimous decision to Fabrício Werdum at Strikeforce: Fedor vs. Rogers.

[13][14][15] Silva defeated former UFC Heavyweight Champion Andrei Arlovski on 15 May 2010, at Strikeforce: Heavy Artillery,[16] via unanimous decision.

On 7 January 2012, Antônio Rodrigo Nogueira told "Portal do Vale Tudo" Silva had signed a UFC contract.

Silva was scheduled to debut against Roy Nelson on 26 May 2012 at UFC 146,[19] but was rescheduled to face Cain Velasquez instead.

[27] Post-fight, Dana White said the bout won Fight of the Night and, despite the draw result, both men would receive their win bonuses.

Following this fight, Silva returned to the hospital for surgery to remove a pituitary gland tumor - which causes his acromegaly - that had reemerged.

[39] Silva lost the bout via knockout in the first round as he was stunned by a right hook on the chin followed with a knee to the body and multiple elbows to the side of his head.

[45] Subsequently, Silva signed with Arena Fighting Championship and was expected to face Chris Barnett at AFC 2 on 12 December 2020, but the whole event was postponed due to multiple COVID-19 cases.

[50] However, his prevailing contract with Eagle Fighting Championship prevented him from competing at the event and he was replaced by Jonathan Ivey.

[54] On December 27, 2022, Silva announced his retirement from MMA competition,[55] intending to continue his involvement in the sport as a grappling and BJJ coach.

[56] However, in April 2023 it was announced that Bigfoot would face Salim El Ouassaidi in the main event of Kingdom Fighting 1 on Saturday the 10th of June.

[57] However on June 18, Silva announced that he is coming out of retirement, expressing interest in a rematch against Salim El Ouassaidi.

[58] Silva fought Juan Espino at La Despedida, in the Gran Canaria Arena, on Saturday the 23rd of March 2024.

[66] The fight was cancelled due to the withdrawal of Silva, who was not medically cleared after suffering a defeat by knockout in his previous bout.

[68] Subsequently, on 28 August 2019, it was announced that Silva would make his promotional debut headlining BKFC 8 against fellow UFC veteran Gabriel Gonzaga on 19 October 2019.