The 1991 Geneva Open was a men's tennis tournament played on clay courts that was part of the World Series of the 1991 ATP Tour. It was the 12th edition of the tournament and was played at Geneva, Switzerland from 9 September through 16 September 1991. Unseeded Thomas Muster won the singles title.
Thomas Muster defeated Horst Skoff 6âÂÂ2, 6âÂÂ4
Sergi Bruguera / Marc Rosset defeated Per Henricsson / Ola Jonsson 3âÂÂ6, 6âÂÂ3, 6âÂÂ2