Nishitama (西多摩郡, Nishitama-gun; West Tama) is a district located in Tokyo Metropolis, Japan. It comprises the village of Hinohara and the following three towns:
Historically, the cities of Ōme, Fussa, Hamura, and Akiruno were parts of Nishitama District but these were broken off from the district after they were elevated to city status.
Western Tokyo, known as the Tama area (多摩地域, Tama chiiki), Tama region (多摩地方, Tama-chihō) or toka (都下) locally, in the Tokyo Metropolis consists of 30 ordinary municipalities (cities (市 shi), towns (町 machi) and one village (村 mura)), unlike the eastern part which consists of 23 special wards.
Before it was transferred to Tokyo in 1893, the Tama area, then also still often referred to as the "three Tama" (三多摩, san-Tama) (referring to the West, North and South Tama counties it consisted of) had formed the Northern part of Kanagawa Prefecture.