The Kinzig is a river, 87 kilometres long, in southern Hesse, Germany. It is a right tributary of the Main. Its source is in the Spessart hills at Sterbfritz, near Schlüchtern. The Kinzig flows into the Main in Hanau. The Main-Kinzig-Kreis (district) was named after the river. The towns along the Kinzig are Schlüchtern, Steinau an der Straße, Bad Soden-Salmünster, Gelnhausen, and Hanau. The Kinzig is first recorded in 815 A.D. as Chinzicha.

The Main is the longest tributary of the Rhine. It rises as the White Main in the Fichtel Mountains of northeastern Bavaria and flows west through central Germany for 525 kilometres (326 mi) to meet the Rhine below Rüsselsheim, Hesse. The cities of Mainz and Wiesbaden are close to the confluence.