内卡河（德语：Neckar）是莱茵河的第四大支流（次于阿勒河、摩泽尔河和美因河），位于德国的巴登-符腾堡州，长367公里。

内卡河发源于施威宁根（Schwenningen），位于黑森林的东部海拔706米的地方。向北流经图宾根、斯图加特和海尔布隆等城市，转而向西流经海德堡，于曼海姆注入莱茵河。

内卡河的流域面积达1点4万平方公里，包括了巴登-符腾堡州的中部大部分地区。

The Neckar (German pronunciation:[ˈnɛkaɐ̯]) is a 367-kilometre-long (228 mi) river in Germany, mainly flowing through the southwestern state of Baden-Württemberg, with a short section through Hesse. The Neckar is a major right tributary of the Rhine. Rising in the Black Forest near Villingen-Schwenningen in the Schwenninger Moos conservation area at a height of 706 m (2,316 ft) above sea level, it passes through Rottweil, Rottenburg am Neckar, Kilchberg, Tübingen, Wernau, Nürtingen, Plochingen, Esslingen, Stuttgart, Ludwigsburg, Marbach, Heilbronn and Heidelberg, before discharging into the Rhine at Mannheim, at 95 m (312 ft) above sea level.