Tajima (但馬国; -no kuni) was an old province of Japan in the area that is today northern Hyogo. Tajima bordered on Harima, Inaba, Tamba Province, and Tango Provinces.

The ancient provincial capital is near the modern town of Hidaka, although a major castle town was built at Izushi. For much of the Sengoku period this area was ruled by the Yamana clan , who submitted to Oda Nobunaga.