The 2005 South American Rugby Championship "B" was the sixth edition of the competition of the second level national rugby union teams in South America.

The tournament was played in Asuncion, on the grounds of the Club Universitario de Rugby de Asunción (CURDA), called "Julio Alvarodo", with five teams participating.

Paraguay won the tournament.

Three points for a victory, two for a draw, and one for a loss