Stefan Ustorf (born January 3, 1974 in Kaufbeuren, West Germany) is a German ice hockey centre who played briefly in the National Hockey League. Drafted 53rd overall in the 1992 NHL Entry Draft by the Washington Capitals, Ustorf played parts of two seasons with the Capitals. After a few years in the minors, he returned to play hockey in Germany.
He played junior hockey in Germany from 1989 to 1991 and represented the country in the 1991, 1992 World Junior Ice Hockey Championships, and 1994 World Junior Ice Hockey Championships. From 1991 to 1994 Ustorf played for ESV Kaufbeuren. In 1994 he went to North America for three seasons, playing a total of 54 NHL games for the Capitals and scored 7 goals and 10 assists.
In 1997 Ustorf returned to Germany and played one season for the Berlin Capitals. The follwoing season he was back in North America for three minor pro seasons. Since 2002 he has played in Germany for various teams in the Deutsche Eishockey Liga.