| Res. | Record | Opponent | Method | Event | Date | Round | Time | Location | Notes |
| Loss | 20–9 | Gadzhi Rabadanov | TKO (punches) | PFL 6 (2025) | June 20, 2025 | 1 | 2:37 | Wichita, Kansas, United States | Return to Lightweight. 2025 PFL Lightweight Tournament Semifinal. |
| Win | 20–8 | Thiago Oliveira | Submission (rear-naked choke) | Lights Out Championship 17 | September 28, 2024 | 1 | 1:58 | Wayne, Michigan, United States | |
| Loss | 19–8 | Rinat Fakhretdinov | Technical Submission (guillotine choke) | UFC on ESPN: Strickland vs. Magomedov | July 1, 2023 | 1 | 0:55 | Las Vegas, Nevada, United States | |
| Win | 19–7 | Diego Sanchez | Decision (unanimous) | Eagle FC 46 | March 11, 2022 | 3 | 5:00 | Miami, Florida, United States | Super Lightweight (165 lb) bout. |
| Loss | 18–7 | Daniel Rodriguez | Decision (unanimous) | UFC on ESPN: Barboza vs. Chikadze | August 28, 2021 | 3 | 5:00 | Las Vegas, Nevada, United States | Return to Welterweight. Lee tested positive for adderall. |
| Loss | 18–6 | Charles Oliveira | Submission (guillotine choke) | UFC Fight Night: Lee vs. Oliveira | March 14, 2020 | 3 | 0:28 | Brasília, Brazil | Catchweight (158.5 lb) bout; Lee missed weight. |
| Win | 18–5 | Gregor Gillespie | KO (head kick) | UFC 244 | November 2, 2019 | 1 | 2:47 | New York City, New York, United States | Return to Lightweight. Performance of the Night. |
| Loss | 17–5 | Rafael dos Anjos | Submission (arm-triangle choke) | UFC Fight Night: dos Anjos vs. Lee | May 18, 2019 | 4 | 3:47 | Rochester, New York, United States | Welterweight debut. |
| Loss | 17–4 | Al Iaquinta | Decision (unanimous) | UFC on Fox: Lee vs. Iaquinta 2 | December 15, 2018 | 5 | 5:00 | Milwaukee, Wisconsin, United States | |
| Win | 17–3 | Edson Barboza | TKO (doctor stoppage) | UFC Fight Night: Barboza vs. Lee | April 21, 2018 | 5 | 2:18 | Atlantic City, New Jersey, United States | Catchweight (157 lb) bout; Lee missed weight. |
| Loss | 16–3 | Tony Ferguson | Submission (triangle choke) | UFC 216 | October 7, 2017 | 3 | 4:02 | Las Vegas, Nevada, United States | For the interim UFC Lightweight Championship. |
| Win | 16–2 | Michael Chiesa | Technical Submission (rear-naked choke) | UFC Fight Night: Chiesa vs. Lee | June 25, 2017 | 1 | 4:37 | Oklahoma City, Oklahoma, United States | Performance of the Night. |
| Win | 15–2 | Francisco Trinaldo | Submission (rear-naked choke) | UFC Fight Night: Belfort vs. Gastelum | March 11, 2017 | 2 | 3:12 | Fortaleza, Brazil | |
| Win | 14–2 | Magomed Mustafaev | Technical Submission (rear-naked choke) | UFC Fight Night: Mousasi vs. Hall 2 | November 19, 2016 | 2 | 4:31 | Belfast, Northern Ireland | Performance of the Night. |
| Win | 13–2 | Jake Matthews | TKO (punches) | The Ultimate Fighter: Team Joanna vs. Team Cláudia Finale | July 8, 2016 | 1 | 4:06 | Las Vegas, Nevada, United States | |
| Win | 12–2 | Efrain Escudero | Decision (unanimous) | UFC 197 | April 23, 2016 | 3 | 5:00 | Las Vegas, Nevada, United States | |
| Loss | 11–2 | Leonardo Santos | TKO (punches) | UFC 194 | December 12, 2015 | 1 | 3:26 | Las Vegas, Nevada, United States | |
| Win | 11–1 | James Moontasri | Submission (rear-naked choke) | UFC Fight Night: Mir vs. Duffee | July 15, 2015 | 1 | 2:56 | San Diego, California, United States | |
| Win | 10–1 | Michel Prazeres | Decision (unanimous) | UFC Fight Night: Henderson vs. Thatch | February 14, 2015 | 3 | 5:00 | Broomfield, Colorado, United States | |
| Win | 9–1 | Jon Tuck | Decision (unanimous) | UFC 178 | September 27, 2014 | 3 | 5:00 | Las Vegas, Nevada, United States | Tuck was deducted one point in round 2 due to a groin kick. |
| Win | 8–1 | Jesse Ronson | Decision (split) | The Ultimate Fighter: Team Edgar vs. Team Penn Finale | July 6, 2014 | 3 | 5:00 | Las Vegas, Nevada, United States | |
| Loss | 7–1 | Al Iaquinta | Decision (unanimous) | UFC 169 | February 1, 2014 | 3 | 5:00 | Newark, New Jersey, United States | |
| Win | 7–0 | Eric Moon | Submission (guillotine choke) | Total Warrior Combat 20 | November 16, 2013 | 1 | 1:24 | Lansing, Michigan, United States | Won the TWC Lightweight Championship. |
| Win | 6–0 | Travis Gervais | Submission (armbar) | Canadian FC 8 | September 13, 2013 | 1 | 0:46 | Winnipeg, Manitoba, Canada | Catchweight (160 lb) bout. |
| Win | 5–0 | Joseph Lile | Submission (rear-naked choke) | Midwest Fight Series 5 | July 19, 2013 | 3 | 1:29 | Indianapolis, Indiana, United States | Catchweight (157 lb) bout; Lee missed weight. |
| Win | 4–0 | Kyle Prepolec | Submission (guillotine choke) | Michiana Fight League 29 | April 13, 2013 | 2 | 2:17 | South Bend, Indiana, United States | Catchweight (158 lb) bout; both fighters missed weight. |
| Win | 3–0 | J. P. Reese | Decision (unanimous) | Impact Fight League 51 | November 17, 2012 | 3 | 5:00 | Auburn Hills, Michigan, United States | |
| Win | 2–0 | Mansour Barnaoui | Decision (unanimous) | Instinct MMA: Instinct Fighting 4 | June 29, 2012 | 3 | 5:00 | Montreal, Quebec, Canada | |
| Win | 1–0 | Levis Labrie | Decision (unanimous) | Instinct MMA: Instinct Fighting 3 | March 31, 2012 | 3 | 5:00 | Sherbrooke, Quebec, Canada | Lightweight debut. |