Professor Marian Smoluchowski (1872–1917): The Forgotten Rector of the Jagiellonian University The article presents the figure of the great Polish physicist Professor Marian Smoluchowski who lived at the turn of the 19th and 20th centuries. It presents his most important achievements as a scientist, a physicist of the Nobel Prize dimension, and in other fields:: didactic, organizational, as well as personal (related to his greatest passion – mountaineering). The study specifies the three most important periods of Smoluchowski’s life and scientific activity: the Vienna, Lviv and Krakow periods, and describes his cooperation with other scholars, mostly of the world-wide renown, such as Albert Einstein. The Viennese period included childhood, education at the Collegium Theresianum, physical studies at the University of Vienna, PhD and habilitation. In Lviv, Smoluchowski spent fourteen years employed at Jan Kazimierz University. There, he developed, among others, the theory of Brownian motion. He spent the last four years of his life in Krakow as a professor at the Jagiellonian University, where he mainly dealt with experimental physics. In 1917 he was elected rector of the University, but in the same year, at the age of 45, he died prematurely of dysentery before taking over this office. He managed to prepare the inaugural lecture “On the uniformity of natural laws.”