Koenen is a patronymic surname of Low German ( ['køːnən]) or Dutch ( ['kunən]) origin derived from the given name Koen (Conrad).
Notable people with the surname include:
Adolf von Koenen (1837–1915), German geologistMathias Koenen (1849–1924), German civil engineerWilhelm Koenen (1886–1963), Communist and East German politicianBernard Koenen (1889–1964), Communist and East German politicianTheo Koenen (1890–1964), German footballerJoannes Henricus Maria Koenen (1893–1956), Dutch neurologist who described Koenen's tumorEmmy Damerius-Koenen (1903–1987), East German politicianHeinrich Koenen (1910–1945), German anti-fascist fighter and Soviet agentLudwig Koenen (born 1931), German-born American philologist and papyrologistGerd Koenen (born 1944), German historian and former communistLyle Koenen (born 1956), American politician in MinnesotaVera Koenen (born 1967), Dutch volleyball playerMichael Koenen (born 1982), American football player