| 1998 NPB season | |
|---|---|
| League | Nippon Professional Baseball |
| Sport | Baseball |
| Regular Season | |
| Season MVP | CL: Kazuhiro Sasaki (YOK) PL: Kazuo Matsui (SEI) |
| League Postseason | |
| CL champions | Yokohama BayStars |
| CL runners-up | Chunichi Dragons |
| PL champions | Seibu Lions |
| PL runners-up | Nippon-Ham Fighters |
| Japan Series | |
| Champions | Yokohama BayStars |
| Runners-up | Seibu Lions |
| Finals MVP | Takanori Suzuki (YOK) |
The 1998 Nippon Professional Baseball season was the 49th season of operation for the league.