Segunda División B
| Founded | 1977 |
|---|---|
| Folded | 2021 |
| Country | Spain |
| Other club(s) from | Andorra (1 team) |
| Divisions | 4 |
| Number of clubs | 4 groups of 20 teams each (80) 3 groups of 20 teams and 2 group of 21, 8 subgroups of 10 teams each and 2 subgroups of 11 in 2020–21 (102) |
| Level on pyramid | 3 |
| Promotion to | Segunda División |
| Relegation to | Tercera División |
| Domestic cup(s) | Copa del Rey Copa Federación |
| Last champions | Burgos (Group 1) Real Sociedad B (Group 2) UD Ibiza (Group 3) Linares Deportivo (Group 4) Badajoz (Group 5) |
| Broadcaster(s) | FORTA: ETB 1, laOtra, tvG2, TPA IB3, TV Melilla Real Madrid TV, SFC TV |
| Website | Official website |
Segunda División B (English: second division B) was the third tier of the Spanish football league system containing 102 teams divided into five groups, until it was replaced by the new structure in 2021. It was administered by the Royal Spanish Football Federation. It was below the top two professional leagues, the Primera División (also known as La Liga) and the Segunda División, and above the Tercera División. The Segunda División B included the reserve teams of a number of La Liga and Segunda División teams. As of the 2023-24 season, its successors are the Primera Federación and the Segunda Federación.
The league's last ever season was in 2020-21. For the 2021–22 season, Segunda División B was replaced by Segunda División RFEF, which became the fourth tier due to the creation of a new, semi-professional third division by the Spanish federation (RFEF) called the Primera División RFEF.