Joanna Jędrzejczyk (; born August 18, 1987) is a Polish former professional mixed martial artist and Muay Thai kickboxer. She has been called the greatest female strawweight mixed martial artist of all time, including by Daniel Cormier, who credited her with putting the weight class "on the map". Jędrzejczyk holds several records in the Ultimate Fighting Championship (UFC), where she is a former UFC Women's Strawweight Champion, including most successful strawweight title defenses (5), most consecutive wins at strawweight (8), and is the first Polish champion and first female European champion. After discovering Muay Thai as a teenager, Jędrzejczyk went on to earn six medals (five gold) at the IFMA World Muaythai Championships and held several different championship titles with promotions such as World Kickboxing Network and World Muaythai Council. Switching to mixed martial arts (MMA) in May 2012, Jędrzejczyk went undefeated in her first nine fights and won the UFC Women's Strawweight Championship in March 2015 after defeating Carla Esparza at UFC 185. Over the next two years, she continued her undefeated streak with five successful title defenses against opponents such as Jessica Penne, Cláudia Gadelha, and Jéssica Andrade. Jędrzejczyk suffered the first loss of her MMA career when she lost the championship to Rose Namajunas in November 2017. After losing a rematch with Namajunas, Jędrzejczyk defeated Tecia Torres before briefly returning to flyweight in an unsuccessful attempt to capture the vacant UFC Women's Flyweight Championship against Valentina Shevchenko in December 2018. Following a strawweight win over Michelle Waterson, Jędrzejczyk faced new strawweight champion Zhang Weili at UFC 248 in March 2020. Jędrzejczyk lost by split decision in what was called the greatest fight in women's MMA history by many pundits. Following a two-year layoff, Jędrzejczyk retired from mixed martial arts in June 2022 after losing a rematch against Zhang at UFC 275. Muay Thai and kickboxing Jędrzejczyk discovered Muay Thai when she was 16, while taking up fitness, which eventually led her to compete in national and European tournaments. Jędrzejczyk competed in Muay Thai and kickboxing for 10 years, winning over 60 matches. Her amateur Muay Thai accomplishments include six IFMA world medals (five gold, one silver) and four IFMA European championships with a record of 37 wins and 3 losses. During her professional career Jędrzejczyk won five world titles including the WKN World Championship, J Girls Championship, WBKF Championship, WKF European Championship, and the WMC Championship. Her