The 2004–05 Segunda Divisão season was the 71st season of the competition and the 55th season of recognised third-tier football in Portugal.
[1] The league was contested by 59 teams in 3 divisions with SC Covilhã, FC Vizela and FC Barreirense winning the respective divisional competitions and gaining promotion to the Liga de Honra.
The overall championship was won by FC Vizela.
[1] CD Alcains Withdrew[1]