ISN

The initials ISN can stand for:


 * Bureau of International Security and Nonproliferation, in the U.S. Department of State
 * Intel Software Network
 * International Relations and Security Network
 * International Socialist Network
 * International Society for Neurochemistry
 * International Society of Nephrology
 * International Suppliers Network, a vendor tracking system
 * Internment Serial Number for US prisoners during conflicts
 * Irish Socialist Network
 * Israel Start-Up Nation
 * ITAD Subscriber Numbers for VoIP PBX
 * Nicaraguan Sign Language (Idioma de Señas de Nicaragua)
 * Sloulin Field International Airport, a defunct airport in North Dakota with the IATA code "ISN"