Kly is a municipality and village in Mělník District in the Central Bohemian Region of the Czech Republic.

Kly consists of seven municipal parts (in brackets population according to the 2021 census):[2] Kly is located about 4 kilometres (2 mi) south of Mělník and 20 km (12 mi) north of Prague.

Part of the Úpor – Černínovsko Nature Reserve is located in the municipal territory.

[3] The I/9 road (which connects the D8 motorway with Česká Lípa and the Czech-German border) passes through the municipality.

The main landmark is the Church of the Nativity of the Virgin Mary in Záboří.