A ransom note is a note or brief letter demanding payment for the return of a hostage. The writing in a ransom note is usually disguised in some way, such as by using letters or words clipped from newspapers or magazines, so that the authors handwriting cannot be linked to the note. The demand specifies the amount of money to be paid or the actions to be taken to satisfy the ransom, and a time limit is usually imposed for responding to the note. Warnings against contacting law enforcement authorities or others are usually included in a ransom note, and the note threatens harm or even death to the hostage should its instructions not be followed. There is usually a particular place and method for delivering the ransom, and the note may also indicate where the hostage may be found if the ransom is satisfied.

In typography, the ransom note effect is the result of using an excessive number of juxtaposed typefaces. It takes its name from the appearance of a stereotypical ransom note or poison pen letter. The writing in a ransom note is usually disguised in some way, such as by using letters or words clipped from newspapers or magazines, so that the authors handwriting cannot be linked to the note.

Overall, a ransom note is a written demand for payment or action in exchange for the release of a hostage, and it is often written in a way that disguises the authors handwriting or identity.