1998–99 Segunda Divisão B

The 1998–99 Segunda Divisão season was the 65th season of the competition and the 49th season of recognised third-tier football in Portugal.

Overview
The league was contested by 54 teams in 3 divisions with SC Covilhã, SC Freamunde and Imortal DC winning the respective divisional competitions and gaining promotion to the Liga de Honra. The overall championship was won by SC Freamunde.