The Waffen Grenadier Regiment of the SS (1st Bulgarian) (German: Waffen-Grenadier Regiment der SS (Bulgarisches Nr. 1)) was formed in World War II when Bulgaria left the Axis powers and joined the Allies in September 1944. It was made up of 600 volunteering Bulgarian workers and soldiers who did not agree with their government's decision to change their allegiance.
Most of the volunteers were in Germany at the time or attached to German military units and were willing to continue the fight against Communism. The unit pledged allegiance to Aleksandar Tsankov's Bulgarian government-in-exile.
The unit was re-equipped with anti-tank weaponry in April 1945 and renamed the SS Panzer Zerstörer Regiment (SS Tank Destroyer Regiment). Germany had hoped the Regiment would provide the nucleus for a new Waffen Grenadier Division of the SS, but as manpower was lacking this goal could not be achieved before the end of the war.