The 1966 French Championships (now known as the French Open) was a tennis tournament that took place on the outdoor clay courts at the Stade Roland-Garros in Paris, France.

The tournament ran from 23 May until 5 June.

It was the 70th staging of the French Championships, and the second Grand Slam tennis event of 1966.

Tony Roche and Ann Jones won the singles titles.

Tony Roche defeated István Gulyás 6–1, 6–4, 7–5 Ann Jones defeated Nancy Richey 6–3, 6–1 Clark Graebner / Dennis Ralston defeated Ilie Năstase / Ion Țiriac 6–3, 6–3, 6–0 Margaret Smith / Judy Tegart defeated Jill Blackman / Fay Toyne 4–6, 6–1, 6–1 Annette Van Zyl / Frew McMillan defeated Ann Jones / Clark Graebner 1–6, 6–3, 6–2