Sinabelkirchen is a Marktgemeinde (market municipality) in the Weiz district of Styria, Austria. It lies in the Ilz River valley in the eastern Styrian Hills, at an elevation of roughly 320 to 330 metres above sea level.
The municipality covers an area of about 37.1 square kilometres. Besides the main village of Sinabelkirchen, it includes a number of hamlets and cadastral communities (Katastralgemeinden), among them Egelsdorf, Frösau, Gnies, Nagl, Obergroßau, Untergroßau and Unterrettenbach.
The South Autobahn (A2) runs through Sinabelkirchen, providing direct highway access to Graz and the wider Vienna–Graz corridor.