Stráž nad Nisou consists of two municipal parts (in brackets population according to the 2021 census):[2] Stráž nad Nisou is located northwest of the centre of Liberec and forms an enclave in the territory of Liberec.

The town is situated at the confluence of the Lusatian Neisse and Černá Nisa rivers.

[3] The I/35 expressway (part of the European route E442) from Liberec to the Czech-German border passes through the municipality.

Stráž nad Nisou is located on the railway lines heading from Liberec to Jindřichovice pod Smrkem and to Černousy.

[7] The main landmark of Stráž nad Nisou is the Church of Saint Catherine.