A circular letter is a written document that is addressed for circulation to a group of people. It is usually formal and official. It may be for a closed group or general distribution. The term may refer to: Flyer (pamphlet), a single page leaflet Newsletter, a report containing news about an organization that is sent to members, customers, employees, or others Circular Letter (Interlingua), an early Interlingua publication Circular letter or encyclical, a letter written by a bishop and addressed to his clergy Massachusetts Circular Letter, a statement written by Samuel Adams