Mackenzie Lynne Dern (born March 24, 1993) is an American and Brazilian professional mixed martial artist and Brazilian Jiu-Jitsu practitioner currently competing in the women's strawweight division of the Ultimate Fighting Championship (UFC), where she is the current UFC Women's Strawweight Champion. She is a former world no. 1 ranked IBJJF competitor, currently ranked 6th among the female divisions. She is an ADCC and no gi BJJ (black belt) world champion. As of March 24, 2026, she is #6 in the UFC women's pound-for-pound rankings.
Dern was born in Phoenix, Arizona. The daughter of Megaton Dias, a highly decorated grappling competitor. As a child, she grew up travelling back and forth between Arizona and her father's native Brazil. Dern is fluent in English and Portuguese. She has stated that Portuguese has become her primary language, explaining that "my dad and stepmom are both Brazilian. My boyfriend speaks Portuguese. I'm speaking Portuguese more than English. I still have lots of interactions in English of course. But I think in Portuguese, anything to do with fight is all in Portuguese in my mind, I dream in Portuguese."
Dern began training by the age of three and practicing with her father and stepmother who is also a black belt, Luciana Tavares. Mackenzie started competing at a young age, and began competing in the adult divisions at 14 years old. She has won a world championship in every belt level as she progressed to black belt rank, and at brown belt she defeated a male Judo black belt on Japanese TV. She was then promoted to black belt by her father in December 2012, three months prior to her 20th birthday. She graduated from Ironwood High School in Glendale, Arizona.
Due to her six 1st place finishes at the Asian Open, Mackenzie is the only female Jiu-Jitsu competitor to have won Gold Medals, at Black Belt level, at each of the 5 principal/highest ranking IBJJF Gi Championships - the other events are the Worlds, the Euros, the Pan Ams and the Brazilian Nationals. One of her biggest achievements in BJJ came when she managed to defeat Gabi Garcia despite a huge weight difference, becoming one of the few women to do so.
Dern was scheduled to make her mixed martial arts debut against Kenia Rosas at Legacy FC 58. She won her debut by unanimous decision.
Dern was scheduled to fight Montana De La Rosa at Legacy FC 61. The bout was initially scheduled to be contested at strawweight, but was later changed to catchweight, as Dern missed weight by 2.8 lbs. She won the fight by a first round submission.
Dern was scheduled to fight Katherine Roy at . Dern came in overweight for the second time in a row, missing weight by four pounds, and had to forfeit 20% of her purse. She won the fight by unanimous decision.
Dern moved up to flyweight for her fourth professional fight, being scheduled to fight Mandy Polk at . She beat Polk by a first-round rear-naked choke.
After going 4âÂÂ0 in her first four professional fights, Dern signed with Invicta Fighting Championship in November 2017.
Dern made her Invicta debut on December 8, 2017, at against Kaline Medeiros. She won the fight via an armbar in round three.
Dern made her promotional debut against Ashley Yoder on March 3, 2018, at UFC 222. She won the fight via split decision.
Dern faced Amanda Cooper on May 12, 2018 at UFC 224. At the weigh-ins, Dern weighed in at 123 pounds, 7 pounds over the strawweight non-title fight upper limit of 116 pounds. As a result, the bout proceeded at catchweight and Dern was fined 30% of her purse. Dern won the fight via submission through a rear naked choke in the first round.
After a hiatus from maternity leave, Dern faced Amanda Ribas on October 12, 2019 at UFC on ESPN+ 19. She lost the fight via unanimous decision.
Dern was expected to face Ariane Carnelossi on April 25, 2020 at UFC Fight Night 173. Carnelossi was forced to withdraw from the bout due to travel restriction.
Dern was scheduled to face Hannah Cifers on April 25, 2020. However, on April 9 the promotion announced that this event was postponed. The pairing eventually took place on May 30, 2020 at . Dern won the fight with a first round kneebar - becoming the first woman to finish a fight by any form of leg lock in UFC history. This win also earned her her first Performance of the Night award.
Dern faced Randa Markos on September 19, 2020 at UFC Fight Night 178. She won the fight via submission in the first round. This win earned her her second straight Performance of the Night award.
Dern faced Virna Jandiroba on December 12, 2020 at UFC 256. Dern won the fight by unanimous decision.
Dern faced Nina Nunes on April 10, 2021 at UFC on ABC 2. She won the bout via first round armbar. This win earned her a Performance of the Night award.
Dern faced Marina Rodriguez on October 9, 2021 on UFC Fight Night 194. She lost the fight via unanimous decision. This fight earned her the Fight of the Night award.
Dern faced Tecia Torres on April 9, 2022 at UFC 273. Dern defeated Torres in a close bout by split decision.
Dern faced Yan Xiaonan on October 1, 2022 at UFC Fight Night 211. She lost the bout via majority decision.
Dern was scheduled to face Angela Hill on May 13, 2023 at UFC on ABC 4. However, the bout was instead moved back one week to headline UFC Fight Night 223. She won the fight via unanimous decision. This fight earned her the Fight of the Night award.
Dern faced former UFC Strawweight Champion Jéssica Andrade on November 11, 2023 at UFC 295. She lost the bout via TKO stoppage in the second round.
Dern faced Amanda Lemos, replacing Tatiana Suarez, on February 17, 2024, at UFC 298. Dern lost by unanimous decision. This fight earned her another Fight of the Night award.
Dern faced Loopy Godinez on August 3, 2024 at UFC on ABC 7. She won the fight by unanimous decision.
Dern was scheduled to face Amanda Ribas in a rematch on December 14, 2024 at UFC on ESPN 63. However, the bout was moved for unknown reasons to January 11, 2025 in order to serve as the main event at UFC Fight Night 249. Dern won the fight via an armbar submission at the end of the third round. This fight earned her another Performance of the Night award.
Dern faced former Invicta FC Strawweight Champion Virna Jandiroba in a rematch on October 25, 2025, at UFC 321 for the vacant UFC Women's Strawweight Championship. She won the championship by unanimous decision.
After 7 years away from the sport, Dern announced her return to professional grappling competition in 2024. She was subsequently invited to compete in the under 55 kg division of the 2024 ADCC World Championship.
Dern withdrew from the 2024 ADCC World Championship, and instead competed against 2022 ADCC world champion Ffion Davies in a superfight at the inaugural Craig Jones Invitational on August 17, 2024. Dern lost the match by submission due to an armbar.
Dern was married to Brazilian professional surfer Wesley Santos. They separated in 2022. After going through divorce proceedings, Dern publicly accused Santos of physical abuse.
In February 2019, Dern announced that she had put her MMA career on hold due to pregnancy. Her daughter was born on June 9, 2019.
According to Dern, she left Black House MMA after a reported incident concerning her original coach, Juan Gomez, where he got into a physical altercation with her husband over a disagreement about money. However, Gomez disputed money being the reason and subsequently both Dern and Gomez were asked to leave the team.
|- |Win |align=center|16âÂÂ5 |Virna Jandiroba |Decision (unanimous) |UFC 321 | |align=center|5 |align=center|5:00 |Abu Dhabi, United Arab Emirates | |- |Win |align=center|15âÂÂ5 |Amanda Ribas |Submission (armbar) | | |align=center|3 |align=center|4:56 |Las Vegas, Nevada, United States | |- |Win |align=center|14âÂÂ5 |Loopy Godinez |Decision (unanimous) | | |align=center|3 |align=center|5:00 |Abu Dhabi, United Arab Emirates | |- |Loss |align=center|13âÂÂ5 |Amanda Lemos |Decision (unanimous) |UFC 298 | |align=center|3 |align=center|5:00 |Anaheim, California, United States | |- |Loss |align=center|13âÂÂ4 |Jéssica Andrade |TKO (punches) |UFC 295 | |align=center|2 |align=center|3:15 |New York City, New York, United States | |- |Win |align=center|13âÂÂ3 |Angela Hill |Decision (unanimous) | | |align=center|5 |align=center|5:00 |Las Vegas, Nevada, United States | |- |Loss |align=center|12âÂÂ3 |Yan Xiaonan |Decision (majority) | | |align=center|5 |align=center|5:00 |Las Vegas, Nevada, United States | |- |Win |align=center|12âÂÂ2 |Tecia Torres |Decision (split) |UFC 273 | |align=center|3 |align=center|5:00 |Jacksonville, Florida, United States | |- |Loss |align=center|11âÂÂ2 |Marina Rodriguez |Decision (unanimous) | | |align=center|5 |align=center|5:00 |Las Vegas, Nevada, United States | |- |Win |align=center|11âÂÂ1 |Nina Nunes |Submission (armbar) | | |align=center|1 |align=center|4:48 |Las Vegas, Nevada, United States | |- |Win |align=center|10âÂÂ1 |Virna Jandiroba |Decision (unanimous) |UFC 256 | |align=center|3 |align=center|5:00 |Las Vegas, Nevada, United States | |- |Win |align=center|9âÂÂ1 |Randa Markos |Submission (armbar) | | |align=center|1 |align=center|3:44 |Las Vegas, Nevada, United States | |- |Win |align=center|8âÂÂ1 |Hannah Cifers |Submission (kneebar) | | |align=center|1 |align=center|2:36 |Las Vegas, Nevada, United States | |- |Loss |align=center|7âÂÂ1 |Amanda Ribas |Decision (unanimous) | | |align=center|3 |align=center|5:00 |Tampa, Florida, United States | |- |Win |align=center|7âÂÂ0 |Amanda Cooper |Submission (rear-naked choke) |UFC 224 | |align=center|1 |align=center|2:27 |Rio de Janeiro, Brazil | |- |Win |align=center|6âÂÂ0 |Ashley Yoder |Decision (split) |UFC 222 | |align=center|3 |align=center|5:00 |Las Vegas, Nevada, United States | |- |Win |align=center|5âÂÂ0 |Kaline Medeiros |Submission (armbar) | | |align=center|3 |align=center|4:45 |Kansas City, Missouri, United States | |- |Win |align=center|4âÂÂ0 |Mandy Polk |Submission (rear-naked choke) | | |align=center|1 |align=center|2:55 |Phoenix, Arizona, United States | |- |Win |align=center|3âÂÂ0 |Katherine Roy |Decision (unanimous) | | |align=center|3 |align=center|5:00 |San Antonio, Texas, United States | |- |Win |align=center|2âÂÂ0 |Montana De La Rosa |Submission (rear-naked choke) |Legacy FC 61 | |align=center|1 |align=center|3:25 |Dallas, Texas, United States | |- |Win |align=center|1âÂÂ0 |Kenia Rosas |Decision (unanimous) |Legacy FC 58 | |align=center|3 |align=center|5:00 |Lake Charles, Louisiana, United States | |-
Records as per BJJHeroes website.
Mitsuyo "Count Koma" Maeda â Carlos Gracie, Sr. â Helio Gracie â Royler Gracie â Megaton Dias â Mackenzie Dern
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