Type 31

Type 31 may refer to:


 * Type 31 frigate, a class of Frigate currently being built for the Royal Navy
 * Type 31 75 mm mountain gun, a field gun of the Imperial Japanese Army
 * a version of the M2 mortar produced in the Republic of China
 * Type 31 Grampus I, a variant of the Bristol Grampus, an early British prototype aircraft
 * Villiers 31, an early French passenger aircraft
 * Tupolev Tu-85, a Soviet prototype aircraft, designated as Type 31 by the US Air Force
 * Hispano-Suiza Type 31, an early Spanish aircraft engine
 * Peugeot Type 31, an early French motor vehicle
 * an early Datsun motor vehicle
 * Type 31 Alphabetical Duplicating Punch, an IBM keypunch