The Disney bomb, also known as the Disney Swish, officially the 4500 lb Concrete Piercing/Rocket Assisted bomb was a 4,500 lb bunker buster bomb developed during the Second World War by the British Royal Navy to penetrate hardened concrete targets, such as submarine pens, which could resist conventional free-fall bombs.

Devised by Royal Navy Captain Edward Terrell, the bomb was fitted with solid-fuel rockets to accelerate its descent, giving it an impact speed of 990 mph (1,590 km/h)—substantially beyond the 750 mph (1,210 km/h) free-fall impact velocity of the 5-tonne Tallboy "earthquake" bomb for comparable purposes.

The Disney could penetrate 16 ft (4.9 m) of solid concrete before detonating. The name is attributed to a propaganda film, Victory Through Air Power, produced by the Walt Disney Studios, a division of The Walt Disney Company, that provided the inspiration for the design.

The Disney bomb saw limited use by the United States Army Air Forces in Europe from February to April 1945. Although it functioned successfully if dropped on a target, it initially could not be dropped accurately enough to attack bunker targets. It was deployed late in the war and had little effect on the Allied bombing campaign against Germany.

During the Second World War, Barnes Wallis developed two large "earthquake" bombs for the Royal Air Force: the five-tonne Tallboy and the ten-tonne Grand Slam, for use against targets too heavily protected to be affected by conventional high-explosive bombs.

These enormous weapons were designed to strike close by their target, to penetrate deeply into the earth, and to cause major structural damage by the shock waves transmitted through the ground. In practice, they proved capable of penetrating a significant thickness of concrete if they scored a direct hit, despite not being designed for that purpose by Wallis, who had to work within the accuracy limitations of current bombsights and the resulting low accuracy of the bombings.

The Disney bomb, by contrast, was designed from the start to penetrate the thick concrete roofs of fortified bunkers. Whereas the earthquake bomb's target was the bunker itself, the Disney bomb's target was the bunker's contents. To this end, the warhead was composed of an unusually thick steel shell containing a comparatively small amount of explosive. It was much slimmer than was usual for aircraft-dropped bombs, and a cluster of booster rockets accelerated the weapon as it fell. These features accord with Newton's approximation for impact depth and the empirical design equation known as Young's equation that states that the deepest target penetration is achieved by a projectile that is dense, long and thin (i.e. has a large sectional density), and strikes with a high velocity.

The CP/RA Disney bombs were 16 ft 6 in (5.03 m) long and weighed 4,500 pounds (2,000 kg). The diameter of the body of the bomb was 11 in (280 mm), while the diameter at the tail was 17 in (430 mm). They were composed of three sections.