Gagnef Municipality (Gagnefs kommun) is a municipality in Dalarna County in central Sweden. Its seat is located in the town of Djurås with 2,257 inhabitants, with the largest town being Mockfjärd with 2365 inhabitants. The locality of Gagnef itself is a smaller village. In 1971 "old" Gagnef was amalgamated with Floda, forming the present municipality. The industry is dominated by small and semi-small companies mainly operating in the forest industry.