NSF

• National Socialist Front, a Swedish National Socialist party • NS-Frauenschaft, the women's wing of the former German Nazi party • National Students Federation, a leftist Pakistani students' political group • Norsk Syndikalistisk Forbund, a Norwegian anarcho-syndicalist group • National Salvation Front (disambiguation), various organizations • National Secessionist Forces, a fictional rebel group in the video game Deus Ex ==Other organizations==

• Naga Students' Federation, student organization of the Naga people • National Science Foundation, a United States government agency • National Service Framework, one of various British health policies • National Sleep Foundation, a U.S. nonprofit organization that promotes public understanding of sleep and sleep disorders • NSF International, formerly the National Sanitation Foundation at the University of Michigan, a food safety standards group • North Sea Fleet • Nykterhetsrörelsens Scoutförbund, a Swedish scouting organization • Norges Speiderforbund, a Norwegian scouting organization • Palestinian National Security Forces • NASASpaceFlight.com, a news website and forum covering spaceflight and aerospace engineering news • , defunct radio and television transmitter company in the Netherlands ==Medicine==

• Nephrogenic systemic fibrosis, a disease • N-ethylmaleimide sensitive fusion protein, an enzyme and gene ==Computing==

• NES Sound Format (.nsf), an audio file format for the Nintendo Entertainment System • Notes Storage Facility (.nsf), the file type for IBM Lotus Notes databases ==Other uses==

• Non-sufficient funds, a cause for a bank to reject a check • New Small Family, an automobile model range • National Service Full-time, a type of conscription in Singapore • Thiazyl fluoride, an unstable gas with the chemical formula NSF • NSF, one of the call signs used by the radio station at the Anacostia Naval Air Station in Washington, D.C.