Blankenhorn is a surname. Notable people with the surname include:
David Blankenhorn (born 1955), American same-sex marriage opponent turned advocate Heber Blankenhorn (1884–1956), American journalist and union activist Herbert Blankenhorn (1904–1991), German diplomat Marion Blankenhorn (1885–1957), American college football coach and physician Travis Blankenhorn (born 1996), American baseball player