Horten is a Norwegian coastal town and municipality in the province of Vestfold in Vestfold and Telemark county. It is located between Holmestrand in the north and Tønsberg in the south. The municipality borders Tønsberg in the south and west, the basic district Mulvika in Holmestrand in the north, and the Oslofjord in the north and east. Horten municipality includes the towns of Horten and Åsgårdstrand, as well as the towns of Nykirke and Skoppum. Horten was the only municipality in the then Vestfold county that was not merged with other municipalities in connection with the municipal reform. Horten is Vestfold and Telemark county's smallest municipality measured in area.

To the east, the municipality has about 40 km of coastline towards the Oslo Fjord, with a coastal path and several large recreation areas. The municipality's area is approx. 71 km², with approx. 27,000 inhabitants, with the bulk of the inhabitants in the old town of Horten (approx. 17,000). The settlement Horten has 20,585 inhabitants as of 1 January 2020. The other settlements in the municipality are Åsgårdstrand with 2,957 inhabitants, Skoppum with 1,701 inhabitants and Nykirke with 699 inhabitants.

Horten has been a ferry terminal for the Horten – Moss ferry route since 1582.