Abies borisii-regis (Bulgarian fir) is a species of fir native to the mountains of the Balkan Peninsula in Bulgaria, northern Greece, North Macedonia, Albania and Serbia. It occurs at altitudes of 800–1,800 m, on mountains with an annual rainfall of over 1,000 mm. The scientific name honours Tsar Boris III of Bulgaria, during whose reign it was described as a new species in 1925. The name is sometimes cited without a hyphen (Abies borisiiregis), though under the provisions of ICBN Article 60.9 the hyphen is to be retained.