| 1988 WTA Tier I Series | |
| Duration: | March 14 – May 9 |
| Tournaments: | 2 |
| Most Tournament Titles: | Steffi Graf (2) |
| Most Tournament Finals: | Steffi Graf (2) |
| Next: | 1989 |
See main article: article and 1988 WTA Tour.
The table below shows the 1988 WTA Tier I Series schedule.
| Tournament | Surface | Week | Winner | Finalist | Semi finalists | Quarter finalists |
|---|---|---|---|---|---|---|
| Key Biscayne | Hard | March 14 | Steffi Graf (1) 6–4, 6–4 |  Chris Evert (2) | Stephanie Rehe Mary Joe Fernandez (15) | Claudia Kohde-Kilsch (6) Barbara Potter (9) Elna Reinach Helena Suková (5) |
| Berlin | Clay | May 9 | Steffi Graf (1) 6–3, 6–2 | Helena Suková (2) | Claudia Kohde-Kilsch (3) Sylvia Hanika (7) |  Nicole Bradtke  Sandra Cecchini (6) Radka Zrubáková Mary Joe Fernandez (8) |