1991 Grand Prix de Tennis de Lyon – Singles

The 1991 Grand Prix de Tennis de Lyon – Singles was an event of the 1991 Grand Prix de Tennis de Lyon men's tennis tournament that was played at the Palais des Sports de Gerland in Lyon, France from 14 October until 21 October 1991. The draw comprised 32 players and eight were seeded. Eighth-seeded Marc Rosset was the defending champion, but lost in the first round to Fabrice Santoro. Second-seeded Pete Sampras won the singles title, defeating unseeded Olivier Delaître, in the final, 6–1, 6–1.

Seeds
• # 🇫🇷 Guy Forget (first round)

• # 🇺🇸 Pete Sampras (champion)

• # 🇪🇸 Sergi Bruguera (semifinals)

• # 🇺🇸 Brad Gilbert (semifinals)

• # 🇺🇸 Derrick Rostagno (first round)

• # 🇦🇷 Alberto Mancini (quarterfinals)

• # 🇸🇪 Jonas Svensson (quarterfinals)

• # Marc Rosset (first round)