1991 U.S. Pro Indoor
| 1991 U.S. Pro Indoor | |
|---|---|
| Date | February 11–18 |
| Edition | 24th |
| Category | Championship Series |
| Draw | 48S / 24D |
| Prize money | $825,000 |
| Surface | Carpet / indoor |
| Location | Philadelphia, PA, United States |
| Venue | Spectrum |
| Champions | |
| Singles | |
| Ivan Lendl | |
| Doubles | |
| Rick Leach / Jim Pugh | |
The 1991 U.S. Pro Indoor was a men's tennis tournament played on indoor carpet courts that was part of the Championship Series of the 1991 ATP Tour. It was the 24th edition of the tournament and was played at the Spectrum in Philadelphia, Pennsylvania in the United States from February 11 to February 18, 1991. First-seeded Ivan Lendl won the singles title, his second at the event after 1986.