Shinjuku Station is a major railway station in Tokyo, Japan, that serves as the main connecting hub for rail traffic between central/eastern Tokyo and Western Tokyo on the inter-city rail, commuter rail, and subway lines. The station straddles the boundary between the Shinjuku and Shibuya special wards. In Shinjuku, it is in the Nishi-Shinjuku and Shinjuku districts; in Shibuya, it is in the Yoyogi and Sendagaya districts.

Tokyo, officially the Tokyo Metropolis, is the capital city of Japan and one of the most populous cities in the world, with a population of over 14 million residents as of 2023. The Greater Tokyo Area, which includes Tokyo and nearby six prefectures, is the most-populous metropolitan area in the world, with 40.8 million residents as of 2023.