is a railway station on the Seibu Shinjuku Line in Nerima Ward, Tokyo, Japan, operated by the private railway operator Seibu Railway. Its station number is SS14.
Musashi-Seki Station is served by the 47.5 km Seibu Shinjuku Line from in Tokyo to in Saitama Prefecture. Located between and , it lies 14.4 km from the Shinjuku terminus. Only all-stations "Local" services and "Semi-Express" services stop at this station.
The station structure is located over the tracks, with one set of ticket barriers, and station entrances on the north and south sides.
The station is composed of two side platforms serving two tracks.
The station opened on 16 April 1927.
Station numbering was introduced on all Seibu Railway lines during fiscal 2012, with Musashi-Seki Station becoming "SS14".
In fiscal 2013, the station was the 34th busiest on the Seibu network with an average of 28,803 passengers daily.
The passenger figures for previous years are as shown below.
North of the station is Honryà «ji Temple, known for the traditional Seki-no-Boroichi flea market, which has been held every December since 1751 during the Edo period.
South of the station is Musashi-Seki Park, a ward-operated park known for its cherry blossoms in spring and rentable boats. The local Ward Office and several Japanese animation studios are also located near the south exit.