E23 may refer to: BMW E23 British submarine HMS E23 European route E23 Sprint Expressway, a major expressway in Kuala Lumpur (designated as E23 in the Malaysian Expressway System) Nimzo-Indian Defense, Encyclopaedia of Chess Openings code Higashi-Meihan Expressway and Ise Expressway, route E23 in Japan Citybus Route E23 in Hong Kong