Brețcu is a commune located in Covasna County within the Transylvania region of Romania. The administrative area consists of three distinct villages: Brețcu, Mărtănuș (also known as Kézdimartonos), and Oituz (also known as Ojtoztelep).
Historical records indicate that the village has been documented under various names over several centuries. These include Bereczk in 1476, Breczko between 1482 and 1496, Bretzku, and Bereck in 1854.