División de Honor B is the second level of Spanish league competition for rugby union clubs.

The league began in 1998 and consists of three groups (North, East and South) of 8 or 9 teams each.

Group A is made up of teams from the northern part of Spain (Asturias, Cantabria, Castilla y León, Galicia, La Rioja, Navarra and Basque Country), Group B is made up of teams from the eastern part (Aragon, Catalonia, Valencian Community, Balearic Islands and Murcia) and Group C is made up of teams from the southern half and central part (Andalusia, Canary Islands, Castilla-La Mancha, Extremadura and Madrid) For promotion to the División de Honor B, the regional competitions follow a system similar to that of promotion from the División de Honor B to the División de Honor, facing the champions of the different divisions between them to decide the promotion to the corresponding group of the División de Honor B.

In the case of relegations, these are automatically made to the corresponding regional competition, leaving it up to the regional federation to fit the new team into the highest regional category, either by increasing the teams for the season or preventing any promotion between its second and highest category to avoid exceeding the number of teams.

There are some regions, such as the Canary Islands or the autonomous cities of Ceuta and Melilla, which have never had a team playing in the División de Honor B.