Simeon Borisov Saxe-Coburg-Gotha is a Bulgarian politician who reigned as the last tsar of the Kingdom of Bulgaria as Simeon II from 1943 until 1946. He was six years old when his father Boris III of Bulgaria died in 1943. Royal power was exercised on his behalf by a regency council led by Simeon's uncle Kiril, Prince of Preslav, General Nikola Mihov and prime minister, Bogdan Filov. In 1946 the monarchy was abolished by referendum, and Simeon was forced into exile.

The Tsardom of Bulgaria, also referred to as the Third Bulgarian Tsardom, sometimes translated in English as the "Kingdom of Bulgaria", or simply Bulgaria, was a constitutional monarchy in Southeastern Europe, which was established on 5 October 1908, when the Bulgarian state was raised from a principality to a tsardom.