Ultimate Fighting Championship
Davis signed with the Ultimate Fighting Championship in December 2009.
Davis made his UFC debut against Brian Stann on February 6, 2010, at UFC 109, winning by unanimous decision.
Davis faced Alexander Gustafsson on April 10, 2010, at UFC 112. Davis defeated Gustafsson via submission (anaconda choke) in the first round, giving Gustafsson his first loss.
Davis next faced Rodney Wallace on August 7, 2010, at UFC 117, replacing the injured Stanislav Nedkov. Davis controlled the bout with his wrestling and won by unanimous decision.
Davis fought Tim Boetsch on November 20, 2010, at UFC 123. He won by a one-handed modified kimura submission later dubbed the "Mr. Wonderful." He was awarded $80,000 for Submission of the Night and received the Submission of the Year award from MMANews247.com.
Davis was expected to face Matt Hamill in Toronto at UFC 129. However, Hamill was tapped as a replacement for Thiago Silva against Rampage Jackson at UFC 130. Davis was offered a fight against Jason Brilz, but then he replaced the injured Tito Ortiz on 6 weeks' notice against Antônio Rogério Nogueira in his first UFC main event on March 26, 2011, at UFC Fight Night 24. Davis defeated Nogueira by unanimous decision.
When UFC Light Heavyweight Champion Jon Jones pulled out of a long-awaited title fight for Rashad Evans, Phil Davis agreed to fight Evans on August 6, 2011, at UFC 133, but on July 12, Davis pulled out of the event with a knee injury and was replaced by Tito Ortiz. Davis was announced to face Lyoto Machida on December 10, 2011, at UFC 140, however, shortly after, it was revealed that Davis was still recovering from a knee injury and the fight did not occur.
Davis faced former UFC Light Heavyweight Champion Rashad Evans in a number one contender fight on January 28, 2012, at UFC on Fox 2. Despite Davis' substantial wrestling credentials, Evans dominated him on the canvas, coasting to a unanimous decision.
Davis was expected to face Chad Griggs on August 4, 2012, at UFC on FOX 4. However, Griggs was forced out of the bout with an injury and was replaced by promotional newcomer Wagner Prado. The fight was ruled "No Contest" after an accidental eye poke at 1:28 of round 1 rendered Prado unable to continue. A rematch with Prado, briefly linked to UFC on FX 5, took place on October 13, 2012, at UFC 153. Davis won the rematch with a second round anaconda choke submission.
Davis was expected to face Forrest Griffin on December 29, 2012, at UFC 155. However, in early December, Griffin pulled out of the bout, citing a knee injury. Davis faced Vinny Magalhães in a wrestler vs. BJJ specialist fight on April 27, 2013, at UFC 159. He won the fight by unanimous decision.
On August 3, 2013, at UFC 163, Davis won a controversial unanimous decision against former UFC Light Heavyweight Champion Lyoto Machida. Davis' only significant advantage was ground and pound following take-downs in the last minute of rounds one and two. While ESPN scored the fight for Davis, 13 selected UFC affiliate media outlets scored the fight in favor of Machida. An SP Nation fanpost stated, "Some MMA commentators and bloggers scored the fight 30–27 for Lyoto Machida." UFC president Dana White tweeted shortly after the fight that he had Machida winning all three rounds, and later told Yahoo! Sports "Machida definitely won", "MMA judging sucks", and his oft-repeated advice: "Never leave it in the hands of the judges." Machida left the light heavyweight division and went on to fight for the UFC Middleweight Championship.
With an official win over the highly ranked Machida, Davis looked to move into title contention against Anthony "Rumble" Johnson who returned to the UFC riding a six-fight win streak at light heavyweight (including one heavyweight fight) outside the promotion, following his disastrous and much-criticised previous UFC run at welterweight. Despite Davis being a considerable betting favorite, on April 26, 2014, in the co-main event at UFC 172, Johnson shut down Davis' wrestling game and kept the fight standing, where his pronounced edge in the striking won him all three rounds in a unanimous decision.
Leading up to the UFC 172 event, Davis actively baited UFC Light Heavyweight Champion Jon Jones on a media promotion conference call. Later, he disparaged Jones' achievements against undersized competition, claiming "against actual light heavyweights, he's been so-so". He predicted that he would soon claim the title, while explicitly dismissing the challenge of his own booked opponent Anthony Johnson. Jones, who defended the UFC Light Heavyweight title against Glover Teixeira at the same event, took pleasure in mocking Davis' loss at the post-fight press conference, and later on-line.
After UFC 172, Davis faced Glover Teixeira who was coming off a loss to UFC Light Heavyweight Champion Jon Jones on the same card. The fight took place October 25, 2014, at UFC 179. He utilized his wrestling advantage and won the fight by unanimous decision.
Having just one fight left of his UFC contract, Davis faced Ryan Bader on January 24, 2015, at UFC on Fox 14. He lost the fight by a close split decision. He did not re-sign with the UFC, finishing his UFC career with a record of 9–3 (1).
In May 2025, Davis filed a class action anti-trust lawsuit, alleges that the UFC's anticompetitive practices also negatively impacted the ability of non-UFC fighters to secure fair wages.
