| Season: | 2005 |
| League Topscorer: | Reinaldo (Santa Cruz) - 16 |
| Nextseason: | Série B 2006 |
The Campeonato Brasileiro Série B 2005, the second level of the Brazilian National League, was played from April 23 to November 26, 2005. The competition had 22 clubs, of which two were promoted to the Série A and six were relegated to the Série C.
In the first round, every team played against each other, much like what happens in the Série A. Differently from the Série A, each team played against the other only once. Thus, each team played 21 games, 11 home and 10 away (or the opposite), for a total of 231 games. The eight best ranked teams advanced to the second round, where they were divided into two groups of four. Teams in each group played against each other home and away. The two best ranked teams in each group advanced to the final round. Those four teams were put into a single group, and played against each other home and away.
The Grêmio finished with the most points, advancing to the Série A along with Santa Cruz. The six last ranked teams in the first round (Anapolina, Bahia, Caxias, Criciúma, União Barbarense and Vitória) were relegated to play the Série C in 2006.