Per Oskar Andersen (born 12 January 1930) is a Norwegian brain researcher at the University of Oslo.
Research by his lab, specifically by Terje Lømo (and Timothy Bliss, who helped characterize the phenomenon years later), led to the discovery of long-term potentiation in 1966.He is a fellow of the Norwegian Academy of Science and Letters and the Royal Society.
He holds honorary degrees at the University of Zürich and the University of Stockholm.He resides in Blommenholm.