Marek Jan Sanak (born 24 November 1958) is a Polish geneticist and molecular biologist, professor of medical sciences, Head of the Department of Molecular Biology and Clinical Genetics of the Jagiellonian University Medical College, Head of the Department of Biochemical and Molecular Diagnostics at the University Hospital in Kraków, the Jagiellonian University Rector's Plenipotentiary for Science and Development in the Medical College, member of the Polish Academy of Learning, and the author of more than 230 original research papers published in peer reviewed journals. In 1997, together with Andrzej Szczeklik, he received the Lancet Investigators Award of The Lancet magazine for their research on bronchial asthma.