Leonhardt is a surname. Notable people with the surname include:
Robert Leonhardt (1877–1923), Austria born baritoneFritz Leonhardt (1909–1999), German civil engineerGustav Leonhardt (1928–2012), Dutch musicianWolfgang Leonhard (1921–2014), German political author, publicist, and historianDavid Leonhardt (1973–), a business journalist, and Pulitzer Prize winner with the New York TimesPaul Saladin LeonhardtJoachim Leonhardt (1929-), German scientist and marksheider