| Res. | Record | Opponent | Method | Event | Date | Round | Time | Location | Notes |
| Loss | 12–6 | Kayla Harrison | Submission (kimura) | UFC 316 | June 7, 2025 | 2 | 4:55 | Newark, New Jersey, United States | Lost the UFC Women's Bantamweight Championship. Peña was deducted one point in round 1 due to illegal upkicks. |
| Win | 12–5 | Raquel Pennington | Decision (split) | UFC 307 | October 5, 2024 | 5 | 5:00 | Salt Lake City, Utah, United States | Won the UFC Women's Bantamweight Championship. |
| Loss | 11–5 | Amanda Nunes | Decision (unanimous) | UFC 277 | July 30, 2022 | 5 | 5:00 | Dallas, Texas, United States | Lost the UFC Women's Bantamweight Championship. |
| Win | 11–4 | Amanda Nunes | Submission (rear-naked choke) | UFC 269 | December 11, 2021 | 2 | 3:26 | Las Vegas, Nevada, United States | Won the UFC Women's Bantamweight Championship. Performance of the Night. |
| Win | 10–4 | Sara McMann | Submission (rear-naked choke) | UFC 257 | January 24, 2021 | 3 | 3:39 | Abu Dhabi, United Arab Emirates | |
| Loss | 9–4 | Germaine de Randamie | Technical submission (guillotine choke) | UFC on ESPN: Holm vs. Aldana | October 4, 2020 | 3 | 3:25 | Abu Dhabi, United Arab Emirates | |
| Win | 9–3 | Nicco Montaño | Decision (unanimous) | UFC Fight Night: de Randamie vs. Ladd | July 13, 2019 | 3 | 5:00 | Sacramento, California, United States | |
| Loss | 8–3 | Valentina Shevchenko | Submission (armbar) | UFC on Fox: Shevchenko vs. Peña | January 28, 2017 | 2 | 4:29 | Denver, Colorado, United States | |
| Win | 8–2 | Cat Zingano | Decision (unanimous) | UFC 200 | July 9, 2016 | 3 | 5:00 | Las Vegas, Nevada, United States | |
| Win | 7–2 | Jessica Eye | Decision (unanimous) | UFC 192 | October 3, 2015 | 3 | 5:00 | Houston, Texas, United States | Eye was deducted one point in round 2 due to an illegal knee. |
| Win | 6–2 | Milana Dudieva | TKO (punches and elbows) | UFC Fight Night: Mendes vs. Lamas | April 4, 2015 | 1 | 3:59 | Fairfax, Virginia, United States | Performance of the Night. |
| Win | 5–2 | Jessica Rakoczy | TKO (punches) | The Ultimate Fighter: Team Rousey vs. Team Tate Finale | November 30, 2013 | 1 | 4:59 | Las Vegas, Nevada, United States | Return to Bantamweight. Won The Ultimate Fighter 18 Bantamweight Tournament. |
| Loss | 4–2 | DeAnna Bennett | Decision (unanimous) | Showdown Fights 10 | February 8, 2013 | 3 | 5:00 | Orem, Utah, United States | Flyweight debut. |
| Loss | 4–1 | Sarah Moras | TKO (doctor stoppage) | ExciteFight: Conquest of the Cage 11 | April 19, 2012 | 2 | 5:00 | Airway Heights, Washington, United States | |
| Win | 4–0 | Rachael Swatez | Submission (guillotine choke) | ExciteFight: Conquest of the Cage 10 | December 15, 2011 | 2 | 0:17 | Airway Heights, Washington, United States | |
| Win | 3–0 | Stephanie Webber | Submission (armbar) | CageSport 8 | December 5, 2009 | 2 | 2:54 | Tacoma, Washington, United States | |
| Win | 2–0 | Robyn Dunne | TKO (punches) | International FC: Caged Combat | August 15, 2009 | 1 | N/A | Penticton, British Columbia, Canada | Catchweight (110 lb) bout. |
| Win | 1–0 | Raylene Harvey | Submission (rear-naked choke) | ExciteFight: Spokane Fight Night 5 | May 9, 2009 | 1 | 2:58 | Spokane, Washington, United States | Bantamweight debut. |