Smuggling is the illegal transportation of objects, substances, information or people, such as out of a house or buildings, into a prison, or across an international border, in violation of applicable laws or other regulations. More broadly, social scientists define smuggling as the purposeful movement across a border in contravention to the relevant legal frameworks.

There are various motivations to smuggle. These include the participation in illegal trade, such as in the drug trade, illegal weapons trade, prostitution, human trafficking, kidnapping, exotic wildlife trade, art theft, blood diamonds, heists, chop shops, illegal immigration or illegal emigration, tax evasion, import/export restrictions, providing contraband to prison inmates, or the theft of the items being smuggled.

Smuggling is a common theme in literature, from Bizet's opera Carmen to the James Bond spy books (and later films) Diamonds Are Forever and Goldfinger.