Navalcarnero
Union Adarve
CD Guadalajara
Cacereno
Melilla
Getafe B
UD San Sebastian Reyes
Socuéllamos
CD Coria
Illescas
CF Talavera
UD Montijo
Villanovense
Conquense
CF Intercity
Tenerife B
Gimnastica Segoviana
Rayo Majadahonda
Fuenlabrada
Eldense
Atletico Madrid B
UD Alzira
CD Badajoz
Mensajero
CD Quintanar del Rey
Numancia
Don Benito
Alcorcon B
La Nucia
CD Diocesano
AD Llerenense
Calvo Sotelo
Orihuela
Rayo Vallecano B
Las Palmas B
At. Pulpileno
Levante B
Union Sur Yaiza
UD San Fernando
Leganes B
Toledo
Elche Ilicitano
Aguilas
Hercules
RSD Alcala
Atletico Mancha Real
Cerdanyola del Valles FC
Marchamalo
CD El Ejido
Real Murcia
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.