DFN

DFN is a three letter acronym that may refer to:


 * Dehcho First Nations, one of the First Nations of North Western Canada
 * Desert Fireball Network, a fireball camera network based in Australia
 * Deutsches Forschungsnetz, the German national research and education network
 * , Definition HTML tag
 * Differential Frequency Noise (electronics)
 * Dignity Freedom Network, formerly the Dalit Freedom Network
 * Direct function (dfn), a way to define a function in the APL programming language
 * Dual Flat No Lead, a style of integrated circuit package