Mario von Appen (sometimes listed as Mario Von Appen or Mario van Appen, born 31 July 1965 in Hamburg) is a German sprint canoeist who competed from the late 1980s to the mid-1990s. At the 1992 Summer Olympics in Barcelona, he won a gold medal in the K-4 1000 m event.
Von Appen also won six medals at the ICF Canoe Sprint World Championships with two golds (K-4 1000 m and K-4 10000 m: both 1993), three silvers (K-4 500 m: 1989, 1993, 1995), and a bronze (K-4 1000 m: 1994).