The Battle of Guadalajara (March 8–23, 1937) saw the People’s Republican Army (Ejército Popular Republicano, or EPR) defeat Italian and Nationalist forces attempting to encircle Madrid during the Spanish Civil War. The Nationalist forces involved in the Battle of Guadalajara were primarily the Italian Corps of Volunteer Troops (Corpo Truppe Volontarie, or CTV).
The battle opened with an Italian offensive on 8 March. This offensive was halted by 11 March. Between 12 March and 14 March, renewed Italian attacks were supported by Spanish Nationalist units. These were halted too. On 15 March, a Republican counter-offensive was prepared. The Republicans successfully launched their counter-offensive from 18 March to 23 March.