A ballistic missile is a missile that follows a prescribed course that cannot be signifigantly altered after the missile has burned its fuel (its course is governed by the laws of ballistics). In order to cover large distances ballistic missiles are usually launched very high into the air or in space, in a sub-orbital spaceflight; for intercontinental missiles the altitude halfway is ca. 1200 km. When in space and no more thrust is provided, the missiles are in freefall.

Long and medium range ballistic missiles are generally designed to deliver nuclear warheads because their payload is too limited for conventional explosives to be efficient.

Many advanced ballistic missiles have several rocket stages and their course can be slightly adjusted from one stage to the next.

Ballistic missiles can vary widely in range and use, and are often divided into categories based on range.

The US distinguishes:

Intercontinental ballistic missile (ICBM): range greater than 5500 km
Intermediate-range ballistic missile (IRBM): range between 3000 and 5500 km
Medium-range ballistic missile (MRBM): range between 1000 and 3000 km
Short-Range Ballistic Missile (SRBM): range less than 1000 km. An example is the Scud.
Medium to short range missiles are often called theatre ballistic missiles (TBM).

Using a missile with a considerably longer range than the distance from launch site to target can make sense: it can reach a higher altitude and come down with a higher speed, making defense more difficult. E.g. a missile with a range 3000 km fired at a target that is only 500 km away could arrive at its target after having reached an altitude of about 1200 km - roughly the height reached by ICBMs. Like them, it would arrive at a speed of typically more than 6 km/s.

The first ballistic missile was the V-2 rocket, developed by Nazi Germany in the 1940s, which was successfully launched for the first time on October 3, 1942 and used for the first time in operation on September 8, 1944.

Specific types of ballistic missiles include:

Ghauri missile
Agni missile
Blue Steel missile
Shaheen missile
Blue Streak missile
Minuteman missile
Hatf missie
SS-24 missile
SS-18 missile
Peacekeeper missile
Polaris missile
Poseidon missile
Prithvi missile
CSS-2 missile
Condor missile
Jericho missile
Nodong-1
Scud
Shahab-3
Shahab-4
Shahab-5
Skybolt ALBM
Trident
V-2
Surya ICBM
Pluton
Hades
ASMP
M45
M51
M5
launched from fixed sites, mobile launchers and submarines.

Specific types of ballistic missile submarines include:

Benjamin Franklin class submarine
Ohio class submarine
Resolution class submarine
Triomphant class
Redoutable class