FDL

FDL may refer to:
 * Fast Deployment Logistics Ship (FDL), U.S. Navy shipbuilding program of the middle 1960s, eventually cancelled (see USNS Lynn (T-AG-182)).
 * Federation of Liberals (Italian: Federazione dei Liberali), an Italian political party
 * Federal Depository Library, a library in the Federal Depository Library Program
 * File Definition Language - used to describe the structure of a Record Management Services file in the OpenVMS operating system.
 * Firebase Dynamic Links, smart URLs that link to any location within iOS, Android or web apps
 * Firedoglake, a defunct political blog
 * Fleur-de-lis (disambiguation)
 * Flexor digitorum longus muscle
 * Florida Democratic League, an American political advocacy group
 * Fond du Lac (disambiguation)
 * Fossa dei Leoni, an Italian football supporters organisation
 * Four Door Lemon, a British video game developer
 * Fonds de Dotation du Libre - Libre Endowment Fund (FDL), French fund to support developers and publishers of Free and Open Source software projects
 * GE FDL, a series of diesel engines
 * GNU Free Documentation License
 * United States Air Force Flight Dynamics Laboratory