NISS

NISS may refer to:


 * National Intelligence and Security Service, an Ethiopian Government agency which gathers information and is tasked with preserving national interest.
 * National Institute of Statistical Sciences, an American institute that researches statistical science and quantitative analysis
 * the National Intelligence and Security Service, the former intelligence service of Sudan, renamed/reorganised in 2019 as the General Intelligence Service (Sudan)
 * Nexus International School Singapore
 * Nordic Institute of Stage and Studio
 * Charles Niss (1861–1938), American politician and businessman
 * Thorvald Niss (1842–1905), Danish painter