1st Mountain Brigade (1. Brygada Górska) was a unit of the Polish Army during the interbellum period, which took part in the Polish September Campaign. Commanded by Colonel Janusz Galadyk, it was part of Operational Group "Bielsko" of the Army Kraków. It consisted mostly of units of the Border Defence Corps (KOP), sent to southwestern Poland from Eastern Borderlands. Created on July 7, 1939, its task was to defend southern wing of the Army, in the section between Żywiec and Rabka.