Coruxo
Marino de Luanco
UP Langreo
Bergantinos
Real Aviles CF
Rayo Cantabria
Compostela
Valladolid Promesas
Deportivo Fabril
Real Oviedo B
Salamanca CF UDS
Pontevedra
Guijuelo
Gimnastica de Torrelavega
Ourense
Numancia
Burgos Promesas
Real Avila
Laredo
Gimnastica Segoviana
Zamora CF
Cristo Atletico
UD Llanera
CD Arenteiro
Lugo B
CD Mostoles URJC
UD Ourense
SD Sarriana
UD Samano
Union Adarve
Arosa
UC Ceares
Lealtad
CD Cayon
Racing Club Villalbes
Arandina
Escobedo
Navalcarnero
Covadonga
Leganes B
Atletico Astorga
Segunda Federación, previously called Segunda RFEF, also officially known as Segunda B, is the fourth tier of the Spanish football league system containing 90 teams divided into five groups. It is administered by the Royal Spanish Football Federation. It is the second tier outside the top two professional leagues, the Primera División (also known as La Liga) and Segunda División (also known as La Liga 2), being behind Primera Federación and above Tercera Federación. The division also includes the reserve teams of a number of La Liga and La Liga 2 teams.
On 6 May 2020, the RFEF announced the creation of a new, two-group, 40-team third division called Primera División RFEF, which resulted in the former third division, Segunda División B, dropping down a level and becoming Segunda División RFEF; the changes were made effective for the 2021–22 campaign.
In July 2022, the division was renamed Segunda Federación.