The Seibu 30000 series (西武30000系) is an electric multiple unit (EMU) train type operated by the private railway operator Seibu Railway on commuter services in the Tokyo area of Japan.

[2] Six-car sets were also scheduled to be built by fiscal 2011, but none were ultimately delivered.

[5] The first train entered service on the Seibu Shinjuku Line on 26 April 2008.

[6] From 8 October 2020, eight-car set 38101 was operated with an all-over Doraemon-themed wrap.

The sides are blue; some doors resemble Doraemon, and others are plain, in line with the rest of the body.