Operational Group Bielsko (Grupa Operacyjna Bielsko, GO Bielsko), named after southern Polish city of Bielsko-Biała, was an Operational Group of the Polish Army which fought in the 1939 Invasion of Poland. Officially created on 23 March 1939, it belonged to Kraków Army, concentrated in southwestern corner of the Second Polish Republic. In the night of 2/3 September 1939, it was renamed into Operational Group Boruta, after General Mieczysław Boruta-Spiechowicz.