The Bulgarian State Railways (Bulgarian: Български държавни железници, Balgarski darzhavni zheleznitsi, abbreviated as БДЖ, BDZ) are Bulgaria's state railway company and the largest railway carrier in the country, established as an entity in 1885. The company's headquarters are located in the capital Sofia. Since the 1990s the BDZ has met serious competition from automotive transport. For the period 1994 to 2010 there is significant drop in the market share in the passenger and freight services and the lack of competent management worsens the situation. Up to 2002 the company owned managed the railway infrastructure in the country, when according to EU regulations a new state company, the National Railway Infrastructure Company, was founded and became the owner of the infrastructure.
Bulgaria is a member of the International Union of Railways (UIC). The UIC Country Code for Bulgaria is 52.