Theft is the act of taking another person's property or services without that person's permission or consent with the intent to deprive the rightful owner of it. The word theft is also used as a synonym or informal shorthand term for some crimes against property, such as larceny, robbery, embezzlement, extortion, blackmail, or receiving stolen property. In some jurisdictions, theft is considered to be synonymous with larceny, while in others, theft is defined more narrowly. Someone who carries out an act of theft may be described as a "thief" (PL: thieves).

Theft is the name of a statutory offence in California, Canada, England and Wales, Hong Kong, Northern Ireland, the Republic of Ireland, and the Australian states of South Australia and Victoria.