Mary Pierce was born in Montreal on 15 January 1975 to a French mother and an American father. She grew up in the United States and was eligible for Canadian, French and American citizenship, and she chose to represent France. She turned professional in March 1989 and made her WTA debut a month later at Hilton Head, aged 14.
Her father coached her for many years; German Aguero of Future Tennis Camps also worked with her free of charge early on. After 1993 she was coached by Nick Bollettieri until early 1996, and later her brother David was her regular coach until 2006. She was one of the hardest hitters on tour: an aggressive baseliner with a strong forehand, a flat two-handed backhand, a powerful first serve and an excellent return. Her weakness was inconsistency, and nerves could affect her.
In 1994 she reached the French Open final, losing to Arantxa Sánchez Vicario. A few months later she beat Sánchez Vicario 6–3, 6–2 in the 1995 Australian Open final, becoming the first Canadian-born player to win a Grand Slam singles title, and on 30 January 1995 she reached world No. 3. Her second major came at Roland Garros in 2000: she beat Conchita Martínez 6–2, 7–5 in the singles final and also won the doubles with Martina Hingis. In 2003 she helped France win the Fed Cup against the United States.
A late revival followed in 2005. She won the Wimbledon mixed doubles with Mahesh Bhupathi and reached two more singles finals, at the French Open against Justine Henin and at the US Open against Kim Clijsters. In all she won 18 singles and 10 doubles titles.
In October 2006 in Linz, leading Vera Zvonareva, she ruptured the anterior cruciate ligament in her left knee. She had surgery that December, missed all of 2007 and never returned to the tour. She now lives in Mauritius and teaches tennis, Roland Garros has an avenue named after her, and she was inducted into the International Tennis Hall of Fame in 2019.