Sipoo is a municipality of Finland. It is part of the Helsinki metropolitan area. The municipality has a population of 22,595 (31 December 2023) and covers an area of 698.60 square kilometres (269.73 sq mi) of which 358.97 km2 (138.60 sq mi) is water. The population density is 66.52 inhabitants per square kilometre (172.3/sq mi). The administrative center of the municipality is Nikkilä, which is located 34 kilometres (21 mi) northeast of the center of Helsinki. Another significant urban area is Söderkulla, located in the southern part of the municipality.

Uusimaa is a region of Finland. It borders the regions of Southwest Finland, Tavastia Proper (Kanta-Häme), Päijänne Tavastia (Päijät-Häme), and Kymenlaakso. Finland's capital and largest city, Helsinki, along with the surrounding metropolitan area, are both contained in the region, and Uusimaa is Finland's most populous region. The population of Uusimaa is 1,734,000.