Bengt Ingemar Samuelsson (born May 21, 1934) is a biochemist. He was born in Halmstad in southwest Sweden and studied at Stockholm University, where he became a professor in 1967. He shared with Sune Bergström the 1982 Nobel Prize for Physiology or Medicine for discoveries concerning prostaglandins and related substances.

Discussing the role of prostaglandins in the body, Samuelsson explained, "It's a control system for the cells that participates in many biological functions. There are endless possibilities of manipulating this system in drug development."

His research interests were originally in cholesterol metabolism with importance to reaction mechanisms. Following the structural work on prostaglandins along with Sune Bergström he has interested mainly in transformation products of arachidonic acid. This has directed to the identification of endoperoxides , thromboxanes and the leukotrienes, and his group has chiefly been involved in studying the chemistry, biochemistry and biology of these compounds and their function in biological control system. The research has implications in numerous clinical areas, especially in thrombosis, inflammation, and allergy.

This field grew enormously since those days. Between 1981 and 1995 about three thousand papers per year were published that openly used the expression "prostaglandins," or related terms such as "prostacyclins," "leukotrienes," and "thromboxanes," in their labels and titles.