The 1947–48 Tercera División was the 12th edition of the Spanish national third tier.
8 geographic groups of 14 clubs (112 in total) participated.
The group winners and runners up qualified for the Fase_Final which was another round robin with the top two clubs earning promotion to Segunda División.
Note: Manchego were reprieved following the resignation of other clubs.
Note: Conquense were reprieved following the resignation of other teams.