The 1999 Sybase Open was a men's tennis tournament played on indoor hard courts at the San Jose Arena in San Jose, California in the United States and was part of the ATP World Series of the 1999 ATP Tour. It was the 110th edition of the tournament ran from February 8 through February 14, 1999.
Champion seeds are indicated in bold text while text in italics indicates the round in which those seeds were eliminated.