Jan Fleischmann started out as a bandy player in the early 1900s but switched to ice hockey. He played in 1906/07 with LTC Praha and PKC Ruch, but the next year joined Slavia Praha, and was with them for the remainder of his career, retiring in 1925. Playing defense, Fleischmann skated at the 1924 Winter Olympics and the European Championships five times in 1911-14 and 1921. He won four European medals, with golds in 1911 and 1914 and silvers in 1913 and 1921. A lawyer, Fleischmann became President of the Czechoslovakian Ice Hockey Federation. Jan was the older brother of Miloslav Fleischmann, and they played together at the 1924 Winter Olympics.