Engelsberg Ironworks (Swedish: Engelsbergs bruk) is an ironworks in Ängelsberg, a village in Fagersta Municipality in Västmanland, Sweden. It was built in 1681 by Per Larsson Gyllenhöök (1645-1706) and developed into one of the world's most modern ironworks in the period 1700–1800. It is listed as a UNESCO world heritage site since 1993.