Tomás Frías is a province in the northern parts of the Bolivian Potosí Department.

The province extends over 115 km from east to west and from north to south.

The main language of the province is Spanish, spoken by 84.5%, while 75.5% of the population speak Quechua.

21% of the population are employed in agriculture, 8% in mining, 10% in industry, 61% in general services.

The people are predominantly indigenous citizens of Quechua and Aymara descent.