2018–19 Segunda División B
The 2018–19 Segunda División B season was the 42nd since its establishment. Eighty teams participated, distributed across four groups of twenty clubs each.
Overview before the season
80 teams joined the league, including three relegated from the 2017–18 Segunda División, 18 promoted from the 2017–18 Tercera División and Ibiza, that replaced Lorca FC after the latter did not fulfill the economic requirements and was banned from playing in Segunda División B.;Relegated from Segunda División:
;Promoted from Tercera División:
- Almería B
- Atlético Levante
- Atlético Malagueño
- Atlético Sanluqueño
- Calahorra
- Castellón
- Conquense
- Cultural Durango
- Don Benito
- Ejea
- Espanyol B
- Gimnástica Torrelavega
- Ibiza
- Internacional
- Langreo
- Oviedo B
- Salamanca UDS
- Teruel
- Unionistas