Rik de Voest (born June 5, 1980 in Milan, Italy) is a professional South African tennis player. As of September 6, 2007, De Voest's career-high ranking was World Number 110, which he achieved on August 21, 2006.
De Voest qualified for the 2007 Wimbledon men's singles event, where he lost to Marat Safin in the first round. De Voest qualified for the U.S. Open later on in 2007, where he defeated Thierry Ascione 6–2, 3–0 before Ascione retired. De Voest went on to lose to John Isner in the following round. De Voest is 12–5 in Davis Cup matches; being 8–5 for singles and 4–0 for doubles.
Playing with Scott Lipsky of the U.S., he won the Levene Gouldin & Thompson Tennis Challenger in Binghamton, New York in 2009.