The Ultimate Fighter reality show In 2009, Pearson competed on the reality TV show
The Ultimate Fighter: United States vs. United Kingdom. He placed first in the lightweight division.
Ultimate Fighting Championship 2010 Pearson defeated
kickboxer Dennis Siver by unanimous decision on 31 March at
UFC Fight Night 21. Pearson was submitted by
Cole Miller via second-round
rear-naked choke on 15 September 2010 at
UFC Fight Night 22. Pearson faced
Spencer Fisher on 27 February 2011 at
UFC 127. He won the fight via unanimous decision.
2011 Pearson lost to
Edson Barboza via split decision at
UFC 134 in a bout that earned
Fight of the Night honours. For his next fight, Pearson dropped to
Featherweight and faced
Junior Assunção on 30 December at
UFC 141. Pearson won the fight by unanimous decision. Pearson faced
Cub Swanson on 22 June 2012 at
UFC on FX 4. He lost the fight by TKO late into the second round.
2012 In July Pearson was confirmed as the Team UK coach for
The Ultimate Fighter: The Smashes. Pearson faced
George Sotiropoulos in a
Lightweight bout on 15 December 2012 at
UFC on FX 6. He won the fight by an early third-round TKO.
2013 Pearson next faced
Ryan Couture on 6 April 2013 at
UFC on Fuel TV 9. He won the fight by TKO in the third round. Pearson faced
Melvin Guillard on 26 October 2013 at
UFC Fight Night 30. The fight ended in a no contest when Pearson was deemed unable to continue after being cut on the forehead by an accidental illegal knee.
2014 A rematch with Guillard was expected to take place on 8 March 2014 at
UFC Fight Night 37. However, Pearson pulled out of the bout citing a knee injury and was replaced by
Michael Johnson. Pearson faced
Diego Sanchez on 7 June 2014 at
UFC Fight Night 42. Despite outstriking Sanchez in every round, and getting a knockdown in round 2, Pearson would ultimate lose the fight by highly controversial split decision. 13 of 14 media scorecards had the bout 30-27 Pearson, while the 14th had Pearson winning 29–28. As a result, Pearson filed an appeal with the New Mexico Athletic Commission, "in hopes the decision is overturned, at the very least to a no-contest." The official decision was ultimately upheld. Despite an official loss on the scorecards, UFC president
Dana White indicated that the organisation had ruled out the possibility of an immediate rematch and said that they would informally treat it as a win for Pearson, and that he would be compensated that way. UFC paid Pearson $30,000 as an unofficial win bonus Pearson was expected to face
Abel Trujillo on 16 August 2014 at
UFC Fight Night 47. However, on 4 August, Trujillo pulled out of the bout and was replaced by
Gray Maynard. He won the fight by TKO in the second round. After a close first round, early in the second round Pearson landed a combination which knocked Maynard down, causing the referee, Keith Peterson, to step in to stop the fight as Maynard was deemed not to be intelligently defending himself. Pearson faced
Al Iaquinta on 8 November 2014 at
UFC Fight Night 55. Despite being the odds-on-favorite, Pearson lost the fight via TKO in the second round.
2015 Pearson faced
Sam Stout on 14 March 2015 at
UFC 185. Pearson won the fight via knockout in the second round dropping Stout with a left hook and finishing him with a right hand on the ground. Subsequently, Pearson won a
Performance of the Night bonus. Pearson faced
Evan Dunham on 18 July 2015 at
UFC Fight Night 72. He lost the fight via unanimous decision. Pearson faced
Paul Felder on 5 September 2015 at
UFC 191. He won the back-and-forth fight by split decision.
2016 Pearson faced
Francisco Trinaldo on 17 January at
UFC Fight Night 81. He lost the fight via unanimous decision. Pearson was expected to face
Abel Trujillo on 20 March at
UFC Fight Night 85. However, Trujillo was removed from the card on 12 March due to alleged
visa issues which restricted his entry to Australia. As a result, Pearson faced
Chad Laprise on the card. He won the fight via split decision. However, Krause was pulled from the fight on 13 June for undisclosed reasons and replaced by
Will Brooks. Pearson lost the fight via unanimous decision. After the loss, Ross Pearson moved to the Welterweight division. Pearson explained that cutting less weight gives him more energy and better sleep. He repeatedly had renal and digestive issues due to the weight cut. Pearson came in as a short notice replacement to face
Jorge Masvidal in a welterweight bout on 30 July at
UFC 201, filling in for an ill
Siyar Bahadurzada. He lost the fight via unanimous decision. A rescheduled bout with
James Krause was scheduled for 19 November at
UFC Fight Night 99. Subsequently, on 26 October, Krause pulled out of the fight citing a torn hamstring. He was replaced by
Stevie Ray. Pearson lost the fight via split decision. Despite the three-fight losing streak, Pearson did not want to retire. He wanted the UFC to host an event at
Newcastle before retirement.
2017 Pearson faced
Dan Hooker on 11 June 2017 at
UFC Fight Night 110. He lost the fight via knockout in the second round.
2018 Pearson faced
Mizuto Hirota on 11 February 2018 at
UFC 221. He won the fight via unanimous decision. Pearson faced
John Makdessi on 28 July 2018 at
UFC on Fox 30. He lost the fight by unanimous decision. This fight earned him the
Fight of the Night award. Pearson was expected to face
Joseph Duffy on 2 December 2018 at
UFC Fight Night 142. However, Pearson announced on 7 November that he was out of the bout due to a broken nose and subsequent surgery to correct the injury.
2019 Pearson faced
Desmond Green on 30 March 2019 at
UFC on ESPN 2. He lost the fight via technical knockout in round one. Pearson announced his retirement on 8 April 2019. Pearson returned to MMA on 16 November to fight Davy Gallon at Probellum 1, losing the fight via KO. ==Fighting style==