Paul-Henri Mathieu (French pronunciation: ; born 12 January 1982) is a retired French tennis player. He won four singles titles on the ATP World Tour. His best singles performance in an ATP World Tour Masters 1000 tournament was reaching the semifinals of the 2005 Canadian Open. He achieved a career-high ATP singles ranking of world No. 12 in April 2008.
Paul-Henri Mathieu was born in Strasbourg, France. He first began playing tennis when he was three and a half years old with his older brother Pierre-Yves. From 1997 to 2000, Paul-Henri trained at the IMG Bollettieri Tennis Academy in Bradenton, Florida before moving back to Paris.
As a junior, Mathieu posted a singles record of 42–15 and a doubles record of 34–12, reaching as high as world no. 6 in singles and world no. 19 in doubles in January 2000. Mathieu won the boys' singles title at the 2000 French Open, defeating Tommy Robredo 3–6, 7–6(7–3), 6–2 in the final.