Letter (message), a form of written communication Mail Letters, the collected correspondence of a writer or historically significant person Maktubat (disambiguation), the Arabic word for collected letters Pauline epistles, addressed by St. Paul to various communities or congregations, such as "Letters to the Galatians" or "Letters to the Corinthians", and part of the canonical books of the Bible The letter as a form of second-person literature; see Epistle Epistulae (Pliny) Epistolary novel, a long-form fiction composed of letters (epistles) Open letter, a public letter as distinguished from private correspondence Letter to the editor, a letter sent to a newspaper, magazine, or online publication by one of its readers and meant to be published Encyclical letter in the Catholic Church Letter (paper size), paper conventionally sized for letter-writing