The Klejnárka is a river which flows through the Central Bohemian Region of the Czech Republic. It is a 40.3-kilometre (25.0 mi) left tributary of the Labe.
The Klejnárka originates in the Bohemian-Moravian Highlands about 5 kilometres (3.1 mi) southwest of Zbýšov, near the village of Dobrovítov. It flows northward through the towns of Čáslav and Nové Dvory (where it is joined by its largest tributary, the Vrchlice). From here it flows another 6 kilometres (3.7 mi) northward to join the Labe river in Starý Kolín.
Coordinates: 50°01′N 15°16′E / 50.017°N 15.267°E