| Res. | Record | Opponent | Method | Event | Date | Round | Time | Location | Notes |
| Loss | 16–9 | Julianna Peña | Decision (split) | UFC 307 | October 5, 2024 | 5 | 5:00 | Salt Lake City, Utah, United States | Lost the UFC Women's Bantamweight Championship. |
| Win | 16–8 | Mayra Bueno Silva | Decision (unanimous) | UFC 297 | January 20, 2024 | 5 | 5:00 | Toronto, Ontario, Canada | Won the vacant UFC Women's Bantamweight Championship. |
| Win | 15–8 | Ketlen Vieira | Decision (split) | UFC Fight Night: Strickland vs. Imavov | January 14, 2023 | 3 | 5:00 | Las Vegas, Nevada, United States | |
| Win | 14–8 | Aspen Ladd | Decision (unanimous) | UFC 273 | April 9, 2022 | 3 | 5:00 | Jacksonville, Florida, United States | Return to Bantamweight. |
| Win | 13–8 | Macy Chiasson | Submission (guillotine choke) | UFC Fight Night: Lewis vs. Daukaus | December 18, 2021 | 2 | 3:07 | Las Vegas, Nevada, United States | Featherweight debut; Chiasson missed weight (148.5 lb). |
| Win | 12–8 | Pannie Kianzad | Decision (unanimous) | UFC Fight Night: Smith vs. Spann | September 18, 2021 | 3 | 5:00 | Las Vegas, Nevada, United States | |
| Win | 11–8 | Marion Reneau | Decision (unanimous) | UFC on ESPN: Blaydes vs. Volkov | June 20, 2020 | 3 | 5:00 | Las Vegas, Nevada, United States | |
| Loss | 10–8 | Holly Holm | Decision (unanimous) | UFC 246 | January 18, 2020 | 3 | 5:00 | Las Vegas, Nevada, United States | |
| Win | 10–7 | Irene Aldana | Decision (split) | UFC on ESPN: dos Anjos vs. Edwards | July 20, 2019 | 3 | 5:00 | San Antonio, Texas, United States | |
| Loss | 9–7 | Germaine de Randamie | Decision (unanimous) | UFC Fight Night: The Korean Zombie vs. Rodríguez | November 10, 2018 | 3 | 5:00 | Denver, Colorado, United States | Catchweight (138 lb) bout; Pennington missed weight. |
| Loss | 9–6 | Amanda Nunes | TKO (punches) | UFC 224 | May 12, 2018 | 5 | 2:36 | Rio de Janeiro, Brazil | For the UFC Women's Bantamweight Championship. |
| Win | 9–5 | Miesha Tate | Decision (unanimous) | UFC 205 | November 12, 2016 | 3 | 5:00 | New York City, New York, United States | |
| Win | 8–5 | Elizabeth Phillips | Decision (unanimous) | UFC 202 | August 20, 2016 | 3 | 5:00 | Las Vegas, Nevada, United States | |
| Win | 7–5 | Bethe Correia | Decision (split) | UFC on Fox: Teixeira vs. Evans | April 16, 2016 | 3 | 5:00 | Tampa, Florida, United States | |
| Win | 6–5 | Jéssica Andrade | Submission (rear-naked choke) | UFC 191 | September 5, 2015 | 2 | 4:58 | Las Vegas, Nevada, United States | Performance of the Night. |
| Loss | 5–5 | Holly Holm | Decision (split) | UFC 184 | February 28, 2015 | 3 | 5:00 | Los Angeles, California, United States | |
| Win | 5–4 | Ashlee Evans-Smith | Technical Submission (bulldog choke) | UFC 181 | December 6, 2014 | 1 | 4:59 | Las Vegas, Nevada, United States | |
| Loss | 4–4 | Jéssica Andrade | Decision (split) | UFC 171 | March 15, 2014 | 3 | 5:00 | Dallas, Texas, United States | |
| Win | 4–3 | Roxanne Modafferi | Decision (unanimous) | The Ultimate Fighter: Team Rousey vs. Team Tate Finale | November 30, 2013 | 3 | 5:00 | Las Vegas, Nevada, United States | |
| Loss | 3–3 | Leslie Smith | Decision (unanimous) | Invicta FC 4 | January 5, 2013 | 3 | 5:00 | Kansas City, Kansas, United States | |
| Loss | 3–2 | Cat Zingano | Submission (rear-naked choke) | Invicta FC 3 | October 6, 2012 | 2 | 3:32 | Kansas City, Kansas, United States | |
| Win | 3–1 | Raquel Pa'aluhi | Submission (guillotine choke) | Destiny MMA: Na Koa 1 | September 8, 2012 | 1 | 3:52 | Honolulu, Hawaii, United States | Won the Destiny MMA Bantamweight Championship. |
| Win | 2–1 | Sarah Moras | Decision (unanimous) | Invicta FC 2 | July 28, 2012 | 3 | 5:00 | Kansas City, Kansas, United States | |
| Loss | 1–1 | Tori Adams | Decision (unanimous) | Rocky Mountain Bad Boyz: A Champion's Quest | June 22, 2012 | 3 | 5:00 | Sheridan, Colorado, United States | Bantamweight debut. |
| Win | 1–0 | Kim Couture | TKO (knees to the body) | Medieval Fight Productions: Vengeance | March 13, 2012 | 2 | 2:25 | Casper, Wyoming, United States | Flyweight debut. |