Margaret Knutson Aase (born 1988) is a Norwegian Brazilian jiu-jitsu and jujutsu practitioner from Kristiansand. She began training jujutsu at the age of eight, inspired by her cousin, and started Brazilian jiu-jitsu at twenty. She holds a black belt under five-time world champion Leticia Ribeiro and represents Gracie Humaita internationally. She also founded her own academy, MKA BJJ, located in Bekkestua outside Oslo. Her competitive record in BJJ is unmatched among Norwegian athletes: she won IBJJF World Championship gold in the gi in both 2011 and 2012, and No-Gi World Championship gold in 2011. She also earned gold at the 2011 European Open and silver at the 2010 IBJJF World Championship. In jujutsu, she won the JJIF U21 World Championship in 2007 and the Grand Slam German Open in 2016. In 2012, she debuted as a professional MMA fighter, defeating Swedish fighter Lina Eklund at the "Rumble of the Kings" event in Linkoping, Sweden. She retired from MMA the following year to focus on BJJ. The same year she won the Viasat 4 TV competition "Norges beste fighter" (Norway's Best Fighter). In 2020, she was one of ten participants on the NRK television show "Mesternes mester" (Masters of Masters), reaching the semi-final. She trained at Frontline Academy in Oslo and with instructor Marcelo Yogui in Brazil before joining the Gracie Humaita women's team under Leticia Ribeiro in the United States. Aase is educated as a sports pedagogue and personal trainer at the Norwegian School of Sport Sciences, holding a bachelor's degree in physical activity and health. She works as a physical education teacher and martial arts instructor.