MLA Handbook (9th ed., 2021), formerly MLA Handbook for Writers of Research Papers (1977–2009), establishes a system for documenting sources in scholarly writing. It is published by the Modern Language Association, which is based in the United States. According to the organization, their MLA style "has been widely adopted for classroom instruction and used worldwide by scholars, journal publishers, and academic and commercial presses".

MLA Handbook began as an abridged student version of MLA Style Manual. Both are academic style guides that have been widely used in the United States, Canada, and other countries, providing guidelines for writing and documentation of research in the humanities, such as English studies (including the English language, writing, and literature written in English); the study of other modern languages and literatures, including comparative literature; literary criticism; media studies; cultural studies; and related disciplines. Released in April 2016, the eighth edition of MLA Handbook (like its previous editions) is addressed primarily to secondary-school and undergraduate college and university teachers and students.

MLA announced in April 2016 that MLA Handbook would henceforth be "the authoritative source for MLA style", and that the 2008 third edition of MLA Style Manual would be the final edition of the larger work. The announcement also stated that the organization "is in the process of developing additional publications to address the professional needs of scholars."