The 33rd Division was one of the divisions of the Spanish Republican Army that were organized during the Spanish Civil War on the basis of the Mixed Brigades.

The unit was created on April 28, 1937,[1] as a reserve division of the Eastern Army.

[2] Command of the unit fell to Eduardo Medrano Rivas.

[3] The unit was later assigned to the IV Army Corps,[4] covering the Guadalajara front.

The 33rd Division played a minor role during the contest.