Avesta Municipality is one of 290 municipalities of Sweden. It is in Dalarna County, in the central part of the country, and its seat is in the town of Avesta.

Dalarna County is a county or län in central Sweden (Svealand). It borders on the counties of Uppsala, Jämtland, Gävleborg, Västmanland, Örebro and Värmland. It also borders on the Norwegian counties of Hedmark and Trøndelag to the west. It was formerly known as Kopparberg County until the name was changed to that of the provincial region on 1 January 1997. The province of Dalarna is slightly larger than the county, as the westernmost part of Ljusdal Municipality belongs to it. Prince Gabriel, the son of Prince Carl Philip, is Duke of Dalarna.