Nova Petrópolis is a municipality in the southern Brazilian state of Rio Grande do Sul. Its main seat, which shares the same name, is the largest settlement within the municipality. The municipality covers an area of 293 km² (113 sq mi).
It lies in the Serra Gaúcha region, at 29º22'35" South, 51º06'52" West, roughly 90 km (56 mi) north of Porto Alegre, the state capital. The municipality sits at an average altitude of 580 m (1,900 ft) above sea level.