Keio Plaza Hotel (京王プラザホテル, Keiō puraza hoteru) is an upscale hotel in the Nishi-Shinjuku district in Shinjuku, Tokyo, Japan and the name of a chain of hotels.
Keio Plaza Hotel is the first skyscraper built in Nishi-Shinjuku and the first high-rise hotel in Japan. The hotel consists of two towers. The first tower is of 178 metres tall and was completed on June 1971, the second tower is 138 metres tall and construction was finished in November 1980. The 1,450-room hotel is a re-development project on the site where a water purification plant (Yodobashi Purification Plant) formerly existed.
The Hotel was the host of the Miss Japan beauty pageants.