In warfare, ramming is a technique that was used in air, sea and land combat. The term originated from battering ram, a siege weapon used to bring down fortifications by hitting it with the force of the ram's momentum. Thus, in warfare ramming refers to hitting a target by running oneself into the target.

Today, hand-held battering rams are one tool among many used by law enforcement and military personnel for door breaching.Forcible entry by criminals has been implemented using such methods as vehicles rammed into buildings.

The ram was commonly used in antiquity, and was an important part of the armament of the galleys of Imperial Rome. The ancient Greeks used their trireme vessels for ramming as well. In ancient China, rams were largely unknown as the lack of a keel and the flat shape of the junk's bow was not conducive to the build of an elongated underwater spur.

The ram's first recorded use in modern times between major warships, however, was in the American Civil War, at the battle of Hampton Roads, when the armoured Confederate warship Virginia rammed the Union frigate Cumberland, sinking her almost immediately.