Extortion is a criminal offense that occurs when a person, organized groups or gangs either obtains money, property or services from another through coercion or intimidation or threatens one with harm unless they are paid money or property. Extortion is commonly practiced by organized crime groups. The actual obtainment of money or property is not required to commit the offense. Making a threat of violence, intent to commit harm or a lawsuit which refers to a requirement of a payment of money or property to halt future violence, harm or lawsuit is sufficient to commit the offense. Four words "pay up or else" are sufficient to constitute the crime of extortion. An extortionate threat made to another in jest is still extortion.

In the United States, extortion may also be committed as a federal crime across a computer system including email, phone, by mail or in using any instrument of "interstate commerce". Extortion requires that the individual sent the message "willingly" and "knowingly" as elements of the crime. The message only has to be sent (but does not have to reach the intended recipient) to commit the crime of extortion.

Extortion is different than blackmail. With blackmail, the blackmailer threatens to do something which would be legal or normally allowed unless paid money or property.