Ida-Viru County is one of 15 counties of Estonia. It is the most north-eastern part of the country. The county contains large deposits of oil shale - the main mineral mined in Estonia. Oil shale is used in the production of shale oil and in thermal power plants. The capital of the county is the town of Jõhvi which is administratively united with the Jõhvi Parish; nevertheless, Narva is the largest town in the county in terms of population and at the same time the third largest city in Estonia after Tallinn and Tartu.

Jõhvi is a town in northeastern Estonia, and the administrative seat of Ida-Viru County and Jõhvi Parish. The town is located about 50 km west of the Estonia–Russia international border.