Infobox last updated on: January 29, 2008.
Sébastien René Grosjean (pronounced ) (born May 29, 1978, Marseille, France) is a professional tennis player from France. His career-high ATP Entry ranking is No. 4 (achieved on October 28, 2002).
Grosjean joined the professional tour in 1996. In 2003 and 2004 he reached the final of the Queen's London Tournament. In the same two years, he also reached the semi-finals of Wimbledon. He finished 2001 as the No. 1 player from his country and for the first time in the top 10 becoming the first Frenchman to finish a year in the top 10 since Cédric Pioline in 1993. In 2001, Grosjean won the Davis Cup with the French team.