Hardt is an Ortsgemeinde – a community belonging to a Verbandsgemeinde – in the Westerwaldkreis in Rhineland-Palatinate, Germany.

The community lies in the Westerwald between Limburg and Siegen.

The river Nister, which is part of the Sieg drainage basin, flows east to west through the municipal area.

Hardt belongs to the Verbandsgemeinde of Bad Marienberg, a kind of collective municipality.

The nearest InterCityExpress stop is the railway station at Montabaur on the Cologne-Frankfurt high-speed rail line.