Voitsberg is a small city in the district of Voitsberg in Styria, Austria, with a population of c. 9,700 as of 2009. It grew upon the St. Margaret church at the Tregistbach river and was first mentioned in 1220 as Civitas. Remains of the Greisenegg palace and Obervoitsberg castle can be seen. Other objects of interest are its Cityhall Voitsberg, designed by architect Arik Brauer.