Karol Marcinkowski (23 June 1800 in Posen, Kingdom of Prussia, today Poznaà  in Poland–6 November 1846) was a Polish physician, social activist in the Greater Poland region (also called the Grand Duchy of Posen), supporter of the basic education (Praca organiczna) programmes, organizer of the Scientific Help Society (Towarzystwo Pomocy Naukowej) and the Poznaà  Bazar (Bazar Poznaà Âski) - the Polish mall in Poznaà  that included a hotel, meeting rooms, crafts and shops.