E31

E31 may refer to:
 * European route E31, a series of roads in Europe
 * Seibu Class E31, a Japanese electric locomotive
 * BMW 8 Series (E31), a 2-door car built by BMW from 1990 to 1999
 * Nimzo-Indian Defence, Leningrad, main line, Encyclopaedia of Chess Openings code
 * Damansara–Shah Alam Elevated Expressway, route E31 in Malaysia
 * Hiroshima-Kure Road, route E31 in Japan
 * Long Win Bus Route E31 in Hong Kong