NS4

NS4 may refer to:

Non-structural protein 4

 * NS4 (HCV) - two viral proteins found in hepatitis C virus:
 * NS4A
 * NS4B
 * Dengue virus NS4a and NS4b
 * West Nile virus NS4A and NS4B

Transportation

 * New Shepard 4, a Blue Origin reusable space launch vehicle booster rocket (booster #4)
 * Blue Origin NS-4, a 2016 April 2 Blue Origin suborbital spaceflight mission for the New Shepard
 * RAF N.S. 4, a British NS class airship
 * Choa Chu Kang MRT/LRT station (station code: ) abbreviated as (NS4/BP1); Singapore
 * Uguisunomori Station (station code: ), Kawanishi, Hyōgo Prefecture, Japan
 * Higashi-Miyahara Station (station code: ), Kita-ku, Saitama, Japan
 * Toyota NS4 - a plug-in hybrid concept car unveiled at the January 2012 North American International Auto Show.

Other

 * Bedford (provincial electoral district), constituency N.S. 04; Nova Scotia, Canada
 * Novelty seeking level 4, disorderliness
 * NS-4; a fictional robot from the 2004 film, "I, Robot"
 * Netscape Communicator - also known as Netscape 4, or NS4