The Manínska tiesňava (literally Manín Gorge in German) is a narrow valley about 0.8 km long between the towns of Považská Teplá and Záskalie (Považská Bystrica district, Trenčín region) in northwestern Slovakia.
The bottom of the gorge, which lies at about 380–390 m above sea level, is occupied by the Manínsky potok stream, which cuts through the Mesozoic limestone formations of the Sulov Mountains (Súľovské vrchy) between Veľký Manín (891 m above sea level) and Malý Manín (813 m above sea level) from the east. With a width of just a few meters at its narrowest point, the Manín Gorge is considered the narrowest gorge in Slovakia. It has only been passable for vehicles since the blasting of a rock in the 1930s made it possible to build a road.
Due to the presence of rare plant and animal species, the Manín Gorge was declared a nature reserve in 1967. Today it is part of the Strážovské vrchy landscape protection area and is connected to the Kostolec Gorge (Kostolecká tiesňava) southeast of Záskalie by an educational trail. Use for climbing is limited to two rock faces in the middle section of the gorge.