The Dimitrov Battalion was part of the International Brigades during the Spanish Civil War. It was the 18th battalion formed, and was named after Georgi Dimitrov, a Bulgarian communist and General Secretary of the Comintern in that period.
It was founded in December 1936, composed largely of Balkan exiles. It soon had 800 volunteers, including about 400 Bulgarians, 160 Greeks and 25 Yugoslavs. It became part of the XV International Brigade on January 31, 1937. There it joined two battalions that were to become famous: the British Battalion and the Lincoln Battalion. They fought together for the first time at the Battle of Jarama in February 1937, with the Dimitrovs holding the right. The brigade suffered extremely heavy casualties.
On September 20, 1937, the Dimitrovs were moved to 45th International Division Reserve, where the battalion was rebuilt. On February 13, 1938, it became part of the newly formed 129th International Brigade, which was formed from central European battalions. It remained with the 129th Brigade until it was demobilised on October 5, 1938. Its last commander, Josef Pavel, became a cabinet minister during Alexander Dubček's Prague Spring in 1968.