The Nagold Valley Railway (German: Nagoldtalbahn) is a railway line in the northern part of the Black Forest in Germany which links Pforzheim with Horb am Neckar and, for most of its route, follows the valley of the River Nagold. Trains on the non-electrified, single-tracked main line are operated by DB Regionalverkehr Alb-Bodensee. Since 2005, the line has been designated and operated as a Kulturbahn ("cultural line"), together with the Upper Neckar Railway from Horb to Tübingen.