The was a commuter electric multiple unit (EMU) train type operated by the private railway operator Odakyu Electric Railway in Japan from 1972 until 2006.
The trains were equipped with 110 kW motors and chopper control.
The fleet consisted of nine four-car and nine six-car sets. The sets were formed as follows.
The trains entered service in 1972, and were the recipient of the 1973 Laurel Prize. Chiyoda Line through services with 9000 series trains began on March 31, 1978. The trains were withdrawn from service in March 2006. A farewell run between and was operated on May 13, 2006.
Trains of a similar design operate on the Roca Line in Argentina.