FSN

FSN may refer to:


 * Fate/stay night, a visual novel
 * Federal State of Novorossiya, a separatist entity in eastern Ukraine
 * Federal Stock Number, a defunct codification system used by the United States federal government
 * Federation of Student Nationalists, the student wing of the Scottish National Party
 * Fjölbrautaskóli Snæfellinga, an Icelandic high school (menntaskóli) located in Grundarfjörður
 * FN Five-seven, a Belgian pistol
 * Fox Sports Networks, an American television network
 * Fox Sports News (Australia), an Australian television channel
 * Fox Sports North, the former name of an American regional sports network by Fox Sports Networks
 * Full Service Network, an American telecommunications company
 * Fu's subcutaneous needle
 * National Social Front (Italian: Fronte Sociale Nazionale), an Italian political party
 * National Salvation Front (Romania) (Romanian: Frontul Salvării Naționale), a defunct Romanian political party