The 1949–50 Tercera División was the 14th edition of the Spanish third national tier.
The group winners and runners up (10 clubs) progressed to the Final Phase.
These 10 clubs were joined by Las Palmas and Tenerife who were not officially members of the Tercera División.
Two groups of 6 were formed with clubs playing home and away (10 matches).
The winners and runners up of each group (4 clubs) were promoted to the Segunda División.