The 1983–84 Segunda División B season was the 7th since its establishment.
40 teams joined the league, including four relegated from the 1982–83 Segunda División and 6 promoted from the 1982–83 Tercera División.
The composition of the groups was determined by the Royal Spanish Football Federation, attending to geographical criteria.
Teams from Andorra, Aragon, Asturias, Basque Country, Catalonia, Galicia and Navarre.
Teams from Andalusia, Aragon, Balearic Islands, Castile and León, Castilla–La Mancha, Catalonia, Ceuta, Extremadura, Madrid, Region of Murcia and Valencian Community.