Biörn Ivemark (1925 – May 8, 2005) was a Swedish pediatrician and pathologist. He is credited with characterizing asplenia with cardiovascular anomalies, also sometimes known as "Ivemark syndrome".
Born in Karlstad, Ivemark graduated from Karolinska Institutet (with a med.lic. degree) in 1951 and received his research doctorate in 1955.
He died at Carcassonne, in southern France, in 2005.