The 1949–50 Tercera División was the 14th edition of the Spanish third national tier.
90 clubs in 5 geographic groups of 18 participated this season. 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. The third and fourth placed teams participated in promotion/relegation play-offs against the teams finishing 14th and 15th in the North and South groups of the Segunda División.