List of prototype World War II combat vehicles

This list contains combat vehicles which never left the design phase or had an extremely limited production (usually < 10).

Australia

 * Australian Cruiser Tank Marks 3 and 4
 * Rhino Heavy Armoured Car

Canada

 * Skink anti-aircraft tank

Germany

 * Entwicklung series, a comprehensive redesign of German armor from small tracked vehicles to a 100-ton superheavy tank. Only a single E-100 chassis was completed
 * Neubaufahrzeug, pre-war heavy tank design, five built.
 * Panther II, development of the Panzerkampfwagen V "Panther". A single chassis was built.
 * Panzerkampfwagen VII "Löwe", a super-heavy tank project that never reached prototype stage.
 * Panzerkampfwagen VIII "Maus", a superheavy tank. Two prototypes built, one used in combat.
 * Panzerkampfwagen IX. Paper project.
 * Panzerkampfwagen X. Paper project.
 * P. 1000 "Ratte". Paper project.
 * P. 1500 "Monster" . Paper project.
 * 12.8 cm Selbstfahrlafette auf VK3001(H) "Sturer Emil", self-propelled anti-tank gun mounting the 128 PaK. Two built and used in front-line combat.
 * Heuschrecke 10, Krupp's design for a new self-propelled artillery gun.

Japan

 * O-I, superheavy tank design in the 130-ton range. Only one supposedly built.

Poland

 * 4TP (light) tank
 * 10TP tank
 * TKW (light) tank
 * PZInż 130 amphibious tank
 * TKS-D tank destroyer

Soviet Union

 * Antonov A-40
 * T-43
 * SMK tank
 * T-100 tank
 * SU-100Y
 * SU-14
 * PPG tankette
 * Object 416

United Kingdom

 * Tank, Heavy, TOG I
 * Tank Heavy, TOG II
 * SP 17pdr, A30 (Avenger) produced and entered service post war
 * Tank, Heavy Assault, "Excelsior" A33
 * Tank, Infantry, Valiant (A38)
 * Tank, Heavy Assault, Tortoise (A39)
 * Tank, Infantry, Black Prince (A43)

United States

 * Medium Tank T20
 * Heavy Tank M6
 * Assault Tank T14
 * T28 Super Heavy Tank
 * Heavy Tank T1
 * T30 Heavy Tank