Loitering is the act of standing or waiting around idly without purpose in some public places. While not being a crime by itself, loitering has historically been treated as an inherent preceding offense to other forms of public crime and disorder, such as prostitution, begging, public drunkenness, dealing in stolen goods, drug dealing, scams, organized crime, robbery, harassment/mobbing, etc. . Loitering provides a lesser offense that can be used by police to confront and deter suspect individuals from lingering in a high-crime area, especially when criminal intent is suspected but not observed.

Loitering laws vary by jurisdiction, but in general, loitering of suspect people can be illegal in some jurisdictions and some specific circumstances. For example, in New York, loitering in the first degree punishes milling about and remaining in a particular place to facilitate becoming intoxicated with a controlled substance, or to possess a controlled substance. Loitering in the first degree is a class B misdemeanor, punishable by up to 90 days in jail.

In Florida, it is unlawful for any person to loiter or prowl in a place, at a time or in a manner not usual for law-abiding individuals, under circumstances that warrant a justifiable and reasonable alarm or immediate concern for the safety of persons or property in the vicinity.

Loitering laws have been challenged and changed over time, and some have been ruled unlawful by the Supreme Court of the United States. Despite this, loitering laws are still in place in many jurisdictions and are used by police to confront and deter suspect individuals from lingering in high-crime areas.