baton or truncheon is a roughly cylindrical club made of wood, rubber, plastic or metal. It is carried as a compliance tool and defensive weapon by law-enforcement officers, correctional staff, security guards and military personnel.

A baton or truncheon may be used in many ways as a weapon. It can be used defensively to block; offensively to strike, jab, or bludgeon; and it can aid in the application of armlocks. The usual striking or bludgeoning action is not produced by a simple and direct hit, as with an ordinary blunt object, but rather by bringing the arm down sharply while allowing the truncheon to pivot nearly freely forward and downward, so moving its tip much faster than its handle. Batons are also used for non-weapon purposes such as breaking windows to free individuals trapped in a vehicle, or turning out a suspect's pockets during a search (as a precaution against sharp objects).

Some criminals use batons as weapons because of their simple construction and easy concealment. The use or carrying of batons or improvised clubs by people other than law enforcement officers is restricted by law in many countries.

Comparison with other law enforcement weapons 

Hand-held impact weapons have some advantages over newer less-lethal weapons. Batons are less expensive than Tasers to buy or to use, and carry none of the risk of cross-contamination of OC aerosol canisters such as pepper spray in confined areas (in houses, if police use pepper spray, the officers may get the spray in their eyes accidentally). Tasers and OC canisters have limited ammunition, whereas batons use none. Like Tasers and pepper spray, batons are referred to as "less-lethal" rather than "non-lethal". That is, these weapons are not designed to be fatal, but they can be. The baton is considered to have a greater risk of lethality than most less-lethal weapons, and so is higher on the use of force continuum than Tasers or OC. While all police weapons can potentially be taken from an officer and used against them, this risk is even greater with batons, as they can be grabbed and pulled away by a suspect if the officer improperly brandishes or swings them.