Riess or Rieß is a German surname. Notable people with the surname include:
Adam Riess (contemporary), American astrophysicistErwin Riess (born 1957), Austrian playwrightFritz Riess (1922–1991), German Formula One race car driverPeter Riess (1804-1883), German Jewish physicistL. W. Riess (1887–1946), American college sports coachLudwig Riess (1861–1928), German-American historian and educatorRyan Riess (born 1990), American professional poker player and 2013 World Series of Poker Main Event championStefan Rieß (born 1988), German professional football playerSusanne Riess-Passer (born 1961), Austrian politician