| Club: | Athletic Bilbao |
| Season: | 1998–99 |
| Mgrtitle: | Head Coach |
| Chrtitle: | President |
| League: | La Liga |
| League Result: | 8th |
| Cup1: | Copa del Rey |
| Cup1 Result: | Round of 16 |
| Cup2: | UEFA Champions League |
| Cup2 Result: | Group stage |
| League Topscorer: | Ismael Urzaiz (16) |
| Season Topscorer: | Ismael Urzaiz (17) |
| Prevseason: | 1997–98 |
| Nextseason: | 1999–2000 |
Athletic had finished second the previous season, and though they gathered only five points fewer - all from losing instead of drawing games - this was enough to drag them down to 8th place.
The club had applied and qualified for the Intertoto Cup, but in the end declined to enter the competition.
Squad at end of season[1]
See main article: 1998–99 La Liga.