Third Mixed Brigade

Third Mixed Brigade Tercera Brigada Mixta
Standard of the Carabineros Corps
Active	1936–1939
Country	Spain
Branch	Spanish Republican Army
Type	Mixed Brigade
Role	Home Defence
Size	Four battalions: The 9th, 10th, 11th and 12th
Part of	10th Division (1936 - 1937) 34th Division (1937 - 1938) 56th Division (1938 - 1939)
Garrison/HQ	Alcázar de San Juan
Engagements	Spanish Civil War
Commanders
Notable commanders	José María Galán

The 3rd Mixed Brigade (Spanish: 3.ª Brigada Mixta), was one of the earliest mixed brigades of the Spanish Republican Army in the Spanish Civil War. It was formed in the fall of 1936 with battalions of the Carabineros corps and saw major action right away in the Defence of Madrid. This brigade also included female combatants —such as Sergeant "La Chata"— and would take part in most of the major battles of the Spanish Civil War, except in the Battle of Jarama.

The brigade's first leader was Carabineros Lieutenant —later Commander— José María Galán, brother of Fermín Galán, leader of the Jaca Uprising, and of Francisco Galán. The mouthpiece of this military unit was the "Tercera Brigada" newspaper.

The Third Mixed Brigade is mentioned in the lyrics of Si me quieres escribir, one of the most famous songs of the Spanish Republican troops during the Civil War.

The 3rd Mixed Brigade was established in October 1936 in Alcázar de San Juan, Ciudad Real Province, though most of its members hailed from Albacete Province. Following a brief period of training the new brigade was sent to the Las Rozas-Majadahonda sector of the Defence of Madrid on 7 November. It began front line combat while still not fully formed, with a total of about 2,500 men. The same day of its baptism of fire the brigade was able to repel a rebel faction attack at Retamares. After a week more troops were added to the brigade, until reaching a total of 3,225. While at the Cantonment zone the brigade staged a counterattack that was a failure.