The Tōbu Keishi Line (東武啓志線, Tōbu Keishi-sen) was a 6.3 km freight railway line operated by Tobu Railway, which ran from Kami-Itabashi Station on the Tōbu Tōjō Line, initially to a Japanese Army arsenal depot in modern-day Hikarigaoka. Following the arrival of US military forces immediately after World War 2, the area was converted to the Grant Heights housing complex (in present-day Hikarigaoka in Tokyo, Japan). The line was named in 1946 after Hugh Boyd Casey, the project engineer for Grant Heights.

This article relies largely or entirely on a single source. (April 2019)

The line opened in 1943 as a freight-only line, and following the opening of Grant Heights, a passenger service was introduced in December 1947, with through services operated to and from the Tojo Line terminus at Ikebukuro, but ceased in February 1948.^[1] The line closed on 22 July 1959.^[1]