Mackenzie Dern is an American-Brazilian black belt from Phoenix, Arizona, and a jiu-jitsu world champion who went on to win a UFC title. She won IBJJF World titles in 2015 and 2016 and ADCC gold in 2015, then moved to MMA. In October 2025 she became UFC women's strawweight champion, and she defended the belt in August 2026.
Background and lineage
Dern grew up on the mats as the daughter of Wellington "Megaton" Dias, a Gracie Humaitá black belt under Royler Gracie. Her stepmother, Luciana Tavares, is also a black belt. She collected IBJJF World, Pan and European titles at blue, purple and brown belt from 2008 to 2012. Her father promoted her to black belt in December 2012, before she turned 20. She now holds a third-degree black belt. For MMA she has trained with MMA Lab, Black House and Checkmat.
Competition highlights
- IBJJF World Championship: featherweight gold at black belt in 2015 and 2016.
- IBJJF World No-Gi: gold at −56 kg in 2014 and in the absolute in 2015.
- ADCC 2015: −60 kg gold, beating Michelle Nicolini in the final on points after a penalty.
- Other IBJJF: Pan titles in 2015 and 2016 and the 2016 European Open.
Her first black belt match was a win over Luiza Monteiro at Copa Pódio in 2013, and she drew with Nicolini at Metamoris 2 that year.
Style and signature techniques
BJJ Heroes lists open guard as her favourite technique. Her finishes lean heavily on leg attacks: the toe hold accounts for 15 of her 45 submission wins on BJJ Heroes. Chokes from back control (6), kneebars (5) and armbars (4) are next. She has used the same tools in the UFC, with kneebar and armbar finishes there.
MMA career
Dern's UFC submissions include a kneebar on Hannah Cifers (2020), armbars on Randa Markos (2020) and Nina Nunes (2021), and an armbar at 4:56 of the third round on Amanda Ribas in January 2025, avenging a 2019 loss. Her losses came against Ribas, Marina Rodriguez, Yan Xiaonan, Jéssica Andrade (her only stoppage loss) and Amanda Lemos. She then won the vacant strawweight title by decision over Virna Jandiroba at UFC 321 and defended it against Gillian Robertson at UFC 330.
She still competes in grappling occasionally. At the 2024 Craig Jones Invitational, Ffion Davies submitted her with an armbar.