Bizen Province (備前国 Bizen-no kuni?) was a province of Japan on the Inland Sea side of Honshū, in what is today the southeastern part of Okayama Prefecture. It was sometimes called Bishū (備州?), with Bitchū and Bingo Provinces. Bizen borders Mimasaka, Harima, and Bitchū Provinces.
Bizen's original center was in the modern city of Okayama. From an early time Bizen was one of Japan's main centers for sword smithing.
In the 3rd month of the 6th year of the Wadō era (713), the land of Bizen-no kuni was administratively separated from Mimasaka Province (美作国). In that same year, Empress Gemmei's Daijō-kan continued to organize other cadastral changes in the provincial map of the Nara period.
In Wadō 6, Tamba Province (丹波国) was sundered from Tango Province (丹後国); and Hyūga Province (日向国) was divided from Ōsumi Province (大隈国). In Wadō 5 (712), Mutsu Province (陸奥国) had been severed from Dewa Province (出羽国).