| 1999 Great American Insurance ATP Championships | |
|---|---|
| Date | August 9–16 |
| Edition | 98th |
| Category | ATP Super 9 |
| Draw | 56S / 28D |
| Prize money | $2,200,000 |
| Surface | Clay |
| Location | Mason, U.S. |
| Champions | |
| Singles | |
 Pete Sampras[1] | |
| Doubles | |
 Jonas Björkman /  Byron Black[2] | |
The 1999 Great American Insurance ATP Championships, also known as the Cincinnati Open, was a men's tennis tournament played on outdoor Clay courts. It was the 98th edition of the tournament previously known as the Thriftway ATP Championships, and was part of the ATP Super 9 of the 1999 ATP Tour. It took place in Mason, Ohio, USA, from August 9 through August 16, 1999. The singles title was won by first-seeded Pete Sampras.[3]
The tournament had previously appeared on the Tier III of the WTA Tour but no event was held from 1989 to 2003.
- ^ "1999 Cincinnati – Singles draw". Association of Tennis Professionals (ATP).
- ^ "1999 Cincinnati – Doubles draw". Association of Tennis Professionals (ATP).
- ^ John Barrett, ed. (2000). ITF World of Tennis 2000. London: CollinsWillow. pp. 163, 164. ISBN 9780002189460.