Bahnsen is a German surname. Notable people with the surname include:
David L. Bahnsen (born 1974), American portfolio manager, author, and television commentator Greg Bahnsen (1948–1995), Calvinist philosopher, apologist, and debater John Bahnsen (1934–2024), United States Army general Julius Bahnsen (1830–1881), German philosopher Karen Bahnsen (born 1960), American college golf coach and former player Ken Bahnsen (born 1930), American football player Stan Bahnsen (born 1944), Major League Baseball pitcher Uwe Bahnsen (1930–2013), German car designer