An advance-fee scam is a form of fraud and is one of the most common types of confidence tricks. The scam typically involves promising the victim a significant share of a large sum of money, in return for a small up-front payment, which the fraudster claims will be used to obtain the large sum. If a victim makes the payment, the fraudster either invents a series of further fees for the victim to pay or simply disappears.

The Federal Bureau of Investigation (FBI) states that "An advance fee scheme occurs when the victim pays money to someone in anticipation of receiving something of greater value - such as a loan, contract, investment, or gift - and then receives little or nothing in return." There are many variations of this type of scam, including the Nigerian prince scam, also known as a 419 scam. The number "419" refers to the section of the Nigerian Criminal Code dealing with fraud and the charges and penalties for such offenders. The scam has been used with fax and traditional mail and is now prevalent in online communications like emails. Other variations include the Spanish Prisoner scam and the black money scam.

Although Nigeria is most often the nation referred to in these scams, they mainly originate in other nations. Other nations known to have a high incidence of advance-fee fraud include: Ivory Coast, Togo, South Africa, the Netherlands, Spain, Poland, and Jamaica.