| Prevseason: | 1997 |
| Nextseason: | 1999 |
| Liga Sudamericana de Básquetbol | |
| Season: | 1998 |
| Champions: |  Atenas |
| Runners Up: |  Cougar Franca |
| Semifinalists: | Boca Juniors Independiente de General Pico |
| Teams: | 16 |
| Dates: | 4 February – 12 May 1998 |
The 1998 Liga Sudamericana de Básquetbol, or 1998 FIBA South American League, was the third edition of the second-tier tournament for professional basketball clubs from South America. The tournament began on 4 February 1998 and finished on 12 May 1998. Defending champions Atenas won their second title, defeating Brazilian club Cougar Franca in the Grand Finals.
Teams were split into four groups of four teams each, and played each other in a home-and-away round-robin format. The top two teams from each group advanced to the final stage, a best-of-three direct playoff elimination where the champion was decided.
| Country | Team |
|---|---|
| | Atenas |
| Boca Juniors | |
| Independiente de General Pico | |
 | Ingavi de La Paz |
| | Marathon Franca |
| Mogi das Cruzes | |
| Universidad Católica | |
| Universidad de Concepción | |
 | Leopardos de Bucamaranga |
 | Ciudad de Loja |
| San José | |
 | Esofa de Lima |
| Aguada | |
| Cordón | |
 | |
| Guaiqueríes de Margarita |
Season MVP: Fabricio Oberto