He is also considered to be one of the best ever, pound-for-pound, to have never fought in the Ultimate Fighting Championship (UFC)[3] Freire was born and grew up in the outskirts of Natal, Brazil.

[5] As a teenager, he trained at the famed Chute Boxe academy alongside notable MMA stars such as Wanderlei Silva and Mauricio Rua.

For the first five and a half years of his career, he competed in his native Brazil and amassed an undefeated record of 12–0 with all but two wins coming by way of stoppage.

Prior to signing with Bellator, Freire was ranked as one of the top prospects outside of the North American fight scene.

[7] At Bellator 18 on May 13, 2010, he won his semifinal bout against fellow Brazilian and former EliteXC Featherweight Champion, Wilson Reis via unanimous decision.

[10] In Bellator Season Four, Freire earned back-to-back third-round KOs against Georgi Karakhanyan and Wilson Reis (a rematch of their bout the previous year) to advance to the finals of the Featherweight Tournament.

[12] He won the fight via unanimous decision and earned a title shot rematch against Joe Warren.

[30] However, after a torn ACL suffered by Karakhanyan, Freire will instead face Bellator Season Ten Featherweight tournament winner Daniel Weichel at the event.

[33] He lost the fight via unanimous decision, dropping the Bellator Featherweight Championship after two successful defenses.

[35] The bout ended in anticlimactic fashion as Freire stopped himself early in round two to declare he had sustained a leg injury.

[36] It was revealed post-fight that Freire had broken his shin in the first round after Henderson checked a low kick with his knee.

[48] He won the fight via TKO in the first round to become the second Bellator fighter after Ryan Bader to hold two titles at the same time.

[57] Freire was knocked down early in the fight, and lost via guillotine choke submission in round one.

[58][59] On October 6, 2021, Freire announced that he vacated the Bellator Lightweight championship, not wanting to get in the way of his brother Patricky's title aspirations.

[68] In the process, Freire attempted to become the first fighter in MMA history to have won three major world championships across three weight classes.

[69][70] Freire faced Chihiro Suzuki in a short notice 154-pound catchweight bout on July 30, 2023, at Bellator MMA x Rizin 2.

[76] On short notice, Freire defended his title against Jeremy Kennedy on March 22, 2024, at Bellator Champions Series 1.

[77] Surviving adversity and a cut, Pitbull won the bout in the third round as he landed a flurry of punches and knees on Kennedy.