1991 Grand Prix de Tennis de Lyon

The 1991 Grand Prix de Tennis de Lyon was a men's tennis tournament played on indoor carpet courts at the Palais des Sports de Gerland in Lyon, France, and was part of the World Series of the 1991 ATP Tour. It was the fifth edition of the tournament and was held from 14 October through 21 October 1991. Second-seeded Pete Sampras won the singles title.

Singles
🇺🇸 Pete Sampras defeated 🇫🇷 Olivier Delaître 6–1, 6–1
 * It was Sampras' 3rd singles title of the year and the 7th of his career.

Doubles
Tom Nijssen / Cyril Suk defeated 🇺🇸 Steve DeVries / 🇦🇺 David Macpherson 7–6, 6–3
 * It was Nijssen's 2nd title of the year and the 6th of his career. It was Suk's 3rd title of the year and the 4th of his career.