Phil Davis competes as a Light Heavyweight for Bellator MMA and is the former Light Heavyweight Champion. As of 1/1/2020, Davis is ranked as the #5 Light Heavyweight in the world according to Fight Matrix.

Davis was born and raised in Harrisburg, Pennsylvania. He began wrestling when he was in the eighth grade and then attended Harrisburg High School where he was a four-year team captain and letterman, with a 112-17 career record. Davis also lettered in tennis and cross-country.

Davis went on to wrestle for the Penn State wrestling team, finishing in 5th place nationally in the 197 lb. weight class as a junior in 2007 and then winning the 197 lb. NCAA title in 2008. He finished with an overall wrestling record of 116–15 while at Penn State and was a four-time NCAA Division I All-American.

After graduating from Penn State, Davis began training in MMA.  In 2009, Davis moved to San Diego. In 2009 he won the No Gi Grappling World Jiu-Jitsu Championship as a blue belt in the 221 lbs, Super Heavyweight division.

Davis began his professional mixed martial arts career in 2008, compiling a record of 4–0 in regional promotions across the United States. Davis signed with the Ultimate Fighting Championship in December 2009.

Davis made his UFC debut against Brian Stann in February, 2010 at UFC 109. Davis won via unanimous decision. Davis faced fellow prospect Alexander Gustafsson in April, 2010 at UFC 112. Davis defeated Gustafsson via submission in the first round, giving Gustafsson his first loss. Davis next faced Rodney Wallace in August, 2010 at UFC 117, replacing an injured Stanislav Nedkov. Davis controlled the bout with his wrestling and won via unanimous decision.

Davis faced Tim Boetsch in November, 2010 at UFC 123. He won by a modified kimura submission 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 fought on short notice against Antônio Rogério Nogueira in March, 2011 at UFC Fight Night 24 and won via unanimous decision.

Davis faced Rashad Evans in January, 2012 at UFC on Fox 2. Davis lost via unanimous decision.

Davis was expected to face Chad Griggs in August, 2012 at UFC on FOX 4. However, Griggs was forced out of the bout with an injury and replaced by promotional newcomer Wagner Prado. The bout was ruled a "No Contest" after an accidental eye poke by Davis rendered Prado unable to continue at 1:28 of round 1. A rematch with Prado took place in October, 2012 at UFC 153. Davis won the rematch with a second round anaconda choke.

Davis faced Vinny Magalhães in April, 2013 at UFC 159. He won the fight via unanimous decision.

Davis faced former UFC Light Heavyweight Champion Lyoto Machida in August, 2013 at UFC 163. Davis defeated Machida via unanimous decision. Davis had takedowns near the end of rounds one and two, but was unable to mount any significant offense.

Davis faced Anthony Johnson in April, 2014 at UFC 172 and lost by unanimous decision.  The loss was Davis' first since 2012. 

Phil Davis cruised to an easy victory over Glover Teixeira at UFC 179 in October 2014 in Rio de Janeiro erasing memories of his loss to Anthony Johnson and removing any doubt that he remains a force to be reckoned with in the UFC.  

Davis faced Ryan Bader on January 24, 2015 at UFC on Fox 14. He lost the fight by split decision, the fight was the last fight on his UFC contract.

Following his final fight in the UFC, Davis parted from the organization and signed with Bellator MMA on April 15, 2015.

Davis made his debut as a participant in Bellator's one-night Light Heavyweight tournament at Bellator MMA & Glory: Dynamite 1 on September 19, 2015.  He faced Emanuel Newton in the opening round and won by submission by Kimura.  He was scheduled to face Muhammed Lawal in the final, however, Lawal was unable to advance to the finals due to a rib injury and was replaced by alternate Francis Carmont. Davis won the bout via knockout in the first round.

By winning the tournament, Davis was set up to face Bellator Light Heavyweight Champion Liam McGeary, however, on February 19, 2016 it was announced that Davis next opponent would be Muhammed Lawal in a number one contender fight on May 14, 2016 at Bellator 154.

Davis won the fight by unanimous decision.

Davis faced Liam McGeary for the Bellator Light Heavyweight Championship in the main event at Bellator 163 on November 4, 2016. He won the bout via unanimous decision to become the new Bellator Light Heavyweight Champion.

Davis faced his former opponent Ryan Bader again in a title fight on June 24, 2017, at Bellator 180. Bader and Davis first met at UFC on Fox: Gustafsson vs. Johnson on January 24, 2015, with Bader winning by split decision. He was defeated again via split decision, thus losing the Bellator title.

Davis faced undefeated Brazilian fighter Leo Leite on November 3, 2017 at Bellator 186. He won the fight via unanimous decision.

Davis faced Linton Vassell on May 25, 2018 at Bellator 200. He won the fight via knock out due to a head kick in round three.

Davis faced Vadim Nemkov on November 15, 2018 Bellator 209. He lost the fight via split decision.

Davis next faced Liam McGeary at Bellator 220 on April 27, 2019. He won the fight via TKO in the third round.

On August 15, 2019, it was announced that Davis had signed an exclusive multi-fight, multi-year contract extension with Bellator.

In his first fight on that contract, Davis faced Karl Albrektsson at Bellator 231 on October 25, 2019. He won the fight via TKO in the third round bringing his professional MMA record to 21-5.

Davis headlined Bellator 245 in a rematch against Lyoto Machida on September 11, 2020. Davis won the fight by split decision for his third straight victory.

On February 9, 2021, it was announced that Davis would be participating in the Bellator Light Heavyweight World Grand Prix Tournament. Davis is scheduled to face Vadim Nemkov for the Bellator Light Heavyweight World Championship in the quarterfinal round. This will be a rematch of their November 2018 bout, which saw Nemkov win via split decision. The bout is scheduled to take place at Bellator 257 on April 16.

Davis faced Yoel Romero on September 18, 2021 at Bellator 266, and won by split decision. Five out of five media outlets scored the fight for Davis.

Davis faced Julius Anglickas on March 12, 2022 at Bellator 276. He won by unanimous decision.