1998 Compaq Grand Slam Cup
| 1998 Compaq Grand Slam Cup | |
|---|---|
| Date | September 28 – October 4 |
| Edition | 9th (men) / 1st (women) |
| Surface | Hard / Indoor |
| Location | Olympiahalle, Munich |
| Champions | |
| Men's Singles | |
 Marcelo Ríos | |
| Women's Singles | |
 Venus Williams | |
The 1998 Compaq Grand Slam Cup was a tennis tournament played on indoor hard courts at the Olympiahalle in Munich in Germany. The event was organized by the International Tennis Federation (ITF), which invited the best-performing players in the year's Grand Slam events to compete in the Grand Slam Cup.
The tournament was held from September 28 through October 4, 1998. The prize money was significant, and therefore the most popular exhibition tournament among the players but there were no ranking points awarded since the ITF had no influence on ATP and WTA who control the ranking system. However the Grand Slam Cup-tournaments would later be recognized by the ATP as official tournaments and a tournament win would be included in the players statistics.
Champions
Men's Singles
Marcelo Ríos defeated Andre Agassi 6–4, 2–6, 7–6(7–1), 5–7, 6–3
- It was Ríos' 6th title of the year and the 11th of his career.
Women's Singles
Venus Williams defeated 
Patty Schnyder 6–2, 3–6, 6–2
- It was Williams' 6th title of the year and the 6th of her career.