| Res. | Record | Opponent | Method | Event | Date | Round | Time | Location | Notes |
| Loss | 19–2 (1) | Demian Maia | Technical Submission (rear-naked choke) | UFC Fight Night: Maia vs. Askren | October 26, 2019 | 3 | 3:54 | Kallang, Singapore | Fight of the Night. |
| Loss | 19–1 (1) | Jorge Masvidal | KO (flying knee) | UFC 239 | July 6, 2019 | 1 | 0:05 | Las Vegas, Nevada, United States | |
| Win | 19–0 (1) | Robbie Lawler | Technical Submission (bulldog choke) | UFC 235 | March 2, 2019 | 1 | 3:20 | Las Vegas, Nevada, United States | |
| Win | 18–0 (1) | Shinya Aoki | TKO (punches) | ONE: Immortal Pursuit | November 24, 2017 | 1 | 0:57 | Kallang, Singapore | Defended the ONE Welterweight Championship. Askren vacated the title on October 27, 2018. |
| Win | 17–0 (1) | Zebaztian Kadestam | TKO (punches) | ONE: Shanghai | September 2, 2017 | 2 | 4:09 | Shanghai, China | Defended the ONE Welterweight Championship. |
| Win | 16–0 (1) | Agilan Thani | Submission (arm-triangle choke) | ONE: Dynasty of Heroes | May 26, 2017 | 1 | 2:20 | Kallang, Singapore | Defended the ONE Welterweight Championship. |
| Win | 15–0 (1) | Nikolay Aleksakhin | Decision (unanimous) | ONE: Global Rivals | April 15, 2016 | 5 | 5:00 | Pasay, Philippines | Non-title bout; Aleksakhin missed weight (187 lb). |
| NC | 14–0 (1) | Luis Santos | No Contest (accidental eye poke) | ONE: Valor of Champions | April 24, 2015 | 1 | 2:19 | Pasay, Philippines | Retained the ONE Welterweight Championship. Accidental eye poke rendered Santos unable to continue. |
| Win | 14–0 | Nobutatsu Suzuki | TKO (punches) | ONE FC: Reign of Champions | August 29, 2014 | 1 | 1:24 | Dubai, United Arab Emirates | Won the ONE Welterweight Championship. |
| Win | 13–0 | Bakhtiyar Abbasov | Submission (arm-triangle choke) | ONE FC 16: Honor and Glory | May 30, 2014 | 1 | 4:21 | Kallang, Singapore | |
| Win | 12–0 | Andrey Koreshkov | TKO (punches) | Bellator 97 | July 31, 2013 | 4 | 2:58 | Rio Rancho, New Mexico, United States | Defended the Bellator Welterweight World Championship. Askren vacated the title on November 14, 2013. |
| Win | 11–0 | Karl Amoussou | TKO (doctor stoppage) | Bellator 86 | January 24, 2013 | 3 | 5:00 | Thackerville, Oklahoma, United States | Defended the Bellator Welterweight World Championship. |
| Win | 10–0 | Douglas Lima | Decision (unanimous) | Bellator 64 | April 6, 2012 | 5 | 5:00 | Windsor, Ontario, Canada | Defended the Bellator Welterweight World Championship. |
| Win | 9–0 | Jay Hieron | Decision (split) | Bellator 56 | October 29, 2011 | 5 | 5:00 | Kansas City, Kansas, United States | Defended the Bellator Welterweight World Championship. |
| Win | 8–0 | Nick Thompson | Decision (unanimous) | Bellator 40 | April 9, 2011 | 3 | 5:00 | Newkirk, Oklahoma, United States | Non-title bout; Thompson missed weight (170.8 lb). |
| Win | 7–0 | Lyman Good | Decision (unanimous) | Bellator 33 | October 21, 2010 | 5 | 5:00 | Philadelphia, Pennsylvania, United States | Won the Bellator Welterweight World Championship. |
| Win | 6–0 | Dan Hornbuckle | Decision (unanimous) | Bellator 22 | June 17, 2010 | 3 | 5:00 | Kansas City, Missouri, United States | Won the Bellator Season 2 Welterweight Tournament. |
| Win | 5–0 | Ryan Thomas | Decision (unanimous) | Bellator 19 | May 20, 2010 | 3 | 5:00 | Grand Prairie, Texas, United States | Bellator Season 2 Welterweight Tournament Semifinal. |
| Win | 4–0 | Ryan Thomas | Technical Submission (guillotine choke) | Bellator 14 | April 15, 2010 | 1 | 2:40 | Chicago, Illinois, United States | Bellator Season 2 Welterweight Tournament Quarterfinal. |
| Win | 3–0 | Matt Delanoit | Submission (north-south choke) | Max Fights DM: Ballroom Brawl | August 28, 2009 | 1 | 1:15 | Des Moines, Iowa, United States | |
| Win | 2–0 | Mitchell Harris | Submission (arm-triangle choke) | Headhunter Productions: The Patriot Act 2 | April 25, 2009 | 1 | 1:27 | Columbia, Missouri, United States | Catchweight (175 lb) bout. |
| Win | 1–0 | Josh Flowers | TKO (punches) | Headhunter Productions: The Patriot Act | February 7, 2009 | 1 | 1:25 | Columbia, Missouri, United States | Welterweight debut. |