In law, fraud is intentional deception to secure unfair or unlawful gain, or to deprive a victim of a legal right. Fraud can violate civil law (e.g., a fraud victim may sue the fraud perpetrator to avoid the fraud or recover monetary compensation) or criminal law (e.g., a fraud perpetrator may be prosecuted and imprisoned by governmental authorities), or it may cause no loss of money, property, or legal right but still be an element of another civil or criminal wrong. The purpose of fraud may be monetary gain or other benefits, for example by obtaining a passport, travel document, or driver's license, or mortgage fraud, where the perpetrator may attempt to qualify for a mortgage by way of false statements.

Internal fraud, also known as "insider fraud", is fraud committed or attempted by someone within an organisation such as an employee.

A hoax is a distinct concept that involves deliberate deception without the intention of gain or of materially damaging or depriving a victim.