Joanna Jędrzejczyk (born August 18, 1987 in Olsztyn) is a Polish MMA, Muay Thai, kickboxing and boxing fighter. The first Polish woman in the MMA organization – the Ultimate Fighting Championship and the champion of this organization in the strawweight (up to 52 kg) in the years 2015–2017.
After winning the UFC belt in 2015, she defended her championship title five times, two-time European champion and four-time amateur world champion, three-time European champion and five-time Polish champion in Thai boxing, vice-champion of Poland in amateur boxing in 2011.