Swatting is a form of criminal harassment that involves deceiving an emergency service (via such means as hoaxing an emergency services dispatcher) into sending a police or emergency response team to another person's location. This is achieved by false reporting of a serious law enforcement emergency, such as a bomb threat, mass shooting, domestic violence, murder, hostage situation, or a false report of a mental health emergency, such as that a person is suicidal or homicidal and armed, among other things.

The term is derived from the law enforcement unit SWAT (Special Weapons and Tactics), a specialized type of police unit in the United States. It is not related to the verb "to swat". SWAT teams are equipped with tactical gear and weapons that differ from patrol units, and are called to situations that are deemed high-risk. A threat may result in evacuations of schools and businesses. Advocates have called for swatting to be considered terrorism due to its use to intimidate and create the risk of injury or death.

Making false reports to emergency services is a criminal offense in many jurisdictions, often punishable by fine or imprisonment. In March 2019, a California man was sentenced to 20 years in prison for carrying out a fatal 2017 swatting. Swatting carries a high risk of violence, and causes resources of about US$10,000 per incident to be wasted by a city or county that responds to a false report of a serious law enforcement emergency, as well as police or municipal liability in cases of violence or use of force. In California, swatters bear the "full cost" of the response, which can lead to fines of up to $10,000 if great bodily injury or death occur as a result of the swatting.

Bomb threats were a concern to police in the 1970s, with public buildings such as airports being evacuated in response to hoax calls designed to cause mass panic and public disruption, or to delay exams at educational institutions. In recent decades, hoax callers sometimes use techniques to disguise their identity or country of origin.

Swatting has origins in prank calls to emergency services. Over the years, callers used increasingly sophisticated techniques to direct response units of particular types. In particular, attempts to have SWAT teams be dispatched to particular locations spawned the term swatting. The term was used by the FBI as early as 2008, and entered Oxford Dictionaries Online in 2015.

In 2019 the Anti-Defamation League estimated that there were about 1,000 swatting incidents nationwide, each costing about $10,000 of police time.

Caller ID spoofing, social engineering, prank calls, and phone phreaking techniques may be variously combined by swatting perpetrators, along with TTY systems meant for the use of those with hearing disabilities. 911 systems (including computer telephony systems and human operators) have been tricked by calls placed from cities hundreds of miles away from the location of the purported call, or even from other countries. The caller typically places a 911 call using a spoofed phone number, hiding the caller's real location.

Swatting is linked to the action of doxing, which is obtaining and broadcasting, often via the Internet, the address and details of an individual with an intent to harass or endanger them.