Aleksander Koj (26 February 1935 – 29 December 2016) was a Polish physician and scientist, a member of Polish Academy of Learning and Polish Academy of Sciences, honorary doctor of Cleveland University and University of Hartford. He was a rector of Jagiellonian University for three cadences: 1987–1990, 1993–1996 and 1996–1999. In his scientific work he is known for researches in the field of immunology, zymology and molecular biology. In 1996 he received Prize of the Foundation for Polish Science for his researches on acute-phase protein.