Staro Petrovo Selo is a village and municipality located in the Brod-Posavina County of Croatia. It is situated within the region of Slavonia, specifically positioned between the southern slopes of the Požeška gora mountain and the Sava river plain.
The settlement lies approximately 12 km (7.5 mi) southeast of Nova Gradiška, nestled between Nova Gradiška and Slavonski Brod. It sits at an elevation of 91 meters above sea level.