| Res. | Record | Opponent | Method | Event | Date | Round | Time | Location | Notes |
| Win | 16–5 | Virna Jandiroba | Decision (unanimous) | UFC 321 | October 25, 2025 | 5 | 5:00 | Abu Dhabi, United Arab Emirates | Won the vacant UFC Women's Strawweight Championship. |
| Win | 15–5 | Amanda Ribas | Submission (armbar) | UFC Fight Night: Dern vs. Ribas 2 | January 11, 2025 | 3 | 4:56 | Las Vegas, Nevada, United States | Performance of the Night. |
| Win | 14–5 | Loopy Godinez | Decision (unanimous) | UFC on ABC: Sandhagen vs. Nurmagomedov | August 3, 2024 | 3 | 5:00 | Abu Dhabi, United Arab Emirates | |
| Loss | 13–5 | Amanda Lemos | Decision (unanimous) | UFC 298 | February 17, 2024 | 3 | 5:00 | Anaheim, California, United States | Fight of the Night. |
| Loss | 13–4 | Jéssica Andrade | TKO (punches) | UFC 295 | November 11, 2023 | 2 | 3:15 | New York City, New York, United States | |
| Win | 13–3 | Angela Hill | Decision (unanimous) | UFC Fight Night: Dern vs. Hill | May 20, 2023 | 5 | 5:00 | Las Vegas, Nevada, United States | Fight of the Night. |
| Loss | 12–3 | Yan Xiaonan | Decision (majority) | UFC Fight Night: Dern vs. Yan | October 1, 2022 | 5 | 5:00 | Las Vegas, Nevada, United States | |
| Win | 12–2 | Tecia Torres | Decision (split) | UFC 273 | April 9, 2022 | 3 | 5:00 | Jacksonville, Florida, United States | |
| Loss | 11–2 | Marina Rodriguez | Decision (unanimous) | UFC Fight Night: Dern vs. Rodriguez | October 9, 2021 | 5 | 5:00 | Las Vegas, Nevada, United States | Fight of the Night. |
| Win | 11–1 | Nina Nunes | Submission (armbar) | UFC on ABC: Vettori vs. Holland | April 10, 2021 | 1 | 4:48 | Las Vegas, Nevada, United States | Performance of the Night. |
| Win | 10–1 | Virna Jandiroba | Decision (unanimous) | UFC 256 | December 12, 2020 | 3 | 5:00 | Las Vegas, Nevada, United States | |
| Win | 9–1 | Randa Markos | Submission (armbar) | UFC Fight Night: Covington vs. Woodley | September 19, 2020 | 1 | 3:44 | Las Vegas, Nevada, United States | Performance of the Night. |
| Win | 8–1 | Hannah Cifers | Submission (kneebar) | UFC on ESPN: Woodley vs. Burns | May 30, 2020 | 1 | 2:36 | Las Vegas, Nevada, United States | Performance of the Night. |
| Loss | 7–1 | Amanda Ribas | Decision (unanimous) | UFC Fight Night: Joanna vs. Waterson | October 12, 2019 | 3 | 5:00 | Tampa, Florida, United States | |
| Win | 7–0 | Amanda Cooper | Submission (rear-naked choke) | UFC 224 | May 12, 2018 | 1 | 2:27 | Rio de Janeiro, Brazil | Catchweight (123 lb) bout; Dern missed weight. |
| Win | 6–0 | Ashley Yoder | Decision (split) | UFC 222 | March 3, 2018 | 3 | 5:00 | Las Vegas, Nevada, United States | |
| Win | 5–0 | Kaline Medeiros | Submission (armbar) | Invicta FC 26 | December 8, 2017 | 3 | 4:45 | Kansas City, Missouri, United States | Return to Strawweight. Performance of the Night. |
| Win | 4–0 | Mandy Polk | Submission (rear-naked choke) | LFA 24 | October 13, 2017 | 1 | 2:55 | Phoenix, Arizona, United States | Flyweight debut. |
| Win | 3–0 | Katherine Roy | Decision (unanimous) | LFA 6 | March 10, 2017 | 3 | 5:00 | San Antonio, Texas, United States | Catchweight (120 lb) bout; Dern missed weight. |
| Win | 2–0 | Montana De La Rosa | Submission (rear-naked choke) | Legacy FC 61 | October 14, 2016 | 1 | 3:25 | Dallas, Texas, United States | Catchweight (118.8 lb) bout; Dern missed weight. |
| Win | 1–0 | Kenia Rosas | Decision (unanimous) | Legacy FC 58 | July 22, 2016 | 3 | 5:00 | Lake Charles, Louisiana, United States | Strawweight debut. |