Gilles Simon (born December 27, 1984 in Nice) is a French professional tennis player. He is a six time winner on the ATP Tour. He is currently the second best French player after Jo-Wilfried Tsonga. Simon is one of the five men to beat Roger Federer, Rafael Nadal and Novak Djokovic since they assumed No.1, No.2 and No.3 positions; the others being Andy Roddick, Andy Murray, David Nalbandian and Jo-Wilfried Tsonga. His coach is French tennis veteran Thierry Tulasne. His ranking as of 19 October 2009 is World No. 12.

Simon was born into a family with no involvement in sport, with his mother being a doctor and his father working in insurance. Supported by his parents, he started playing tennis at the age of 6. He progressed considerably as a teenager as he started to compete in junior tournaments in France. He cites Michael Chang as a major influence, as his comparatively small frame proved that size wasn't an important factor in playing tennis.

Simon began his professional tennis career in the summer of 2002, competing at multiple Futures tournaments in France before playing in international tournaments. His first Futures title came in Lisbon, Portugal, in June 2003, and reached the quarterfinals of three other tournaments. He then captured his second title in Jamaica in September. During 2004 he saw three wins in France and another in Algeria.