Sieghartskirchen is a municipality in the district of Tulln, in the Austrian state of Lower Austria. It lies in the northeastern part of the country, within the federal province that surrounds Vienna.
Administratively, Sieghartskirchen belongs to the Tulln district, one of the districts that make up Lower Austria. As a municipality, it is a local government unit that may comprise the main town along with associated settlements and cadastral communities.
Beyond its status as a municipality in Tulln district, Lower Austria, few details are recorded in the available source material. It is one of the many small municipalities that make up the administrative fabric of the region around Vienna.