20 series

20 series could refer to:
*The original designation of the JNR 181 series sets
*Enoden 20 series, an articulated suburban EMU used by Enoshima Electric Railway since April 2002
*Ichibata DeHa 20 series, a suburban EMU used by Ichibata Electric Railway from 1951 to 1996
*Kagoshima City Tram 20 series, a decorated streetcar used by the Kagoshima Municipal Transport Bureau since 1978
*Nishitetsu 20 series, a suburban EMU used by Nishi-Nippon Railroad from 1958 to 1991
*Osaka Metro 20 series, a city commuter EMU used by Osaka Metro on the Chūō Line since December 1984
*Osaka Metro New 20 series, an evolution of the 20 series sets used on a variety of lines since May 1991