Null

Null may refer to:

Astronomy

 * Nuller, an optical tool using interferometry to block certain sources of light

Computing

 * Null (SQL) (or NULL), a special marker and keyword in SQL indicating that something has no value
 * Null character, the zero-valued ASCII character, also designated by NUL, often used as a terminator, separator or filler. This symbol has no visual representation.
 * Null device, a virtual file that discards data written to it, on Unix systems
 * Null pointer or reference (sometimes written,  , or  ), an object pointer (or reference) not currently set to point (or refer) to a valid object

Mathematics

 * Null (mathematics), a zero value in several branches of mathematics

Physics

 * Null (physics), a point in a field where the field quantity is zero
 * Null (radio), a concept in electromagnetism

Arts and media

 * The Null Corporation, an imprint of the band Nine Inch Nails
 * Null (Intronaut EP), 2006
 * Null (Foetus EP), 1995
 * Null, an identity of the character Gray Fox in the Metal Gear Solid: Portable Ops video game
 * Null, a villain from Teenage Mutant Ninja Turtles Adventures

People with the surname

 * Christopher Null (born 1971), American writer and film critic
 * Eduard van der Nüll (1812–1868), Austrian architect
 * Gary Null (born 1945), American radio host and author of works about alternative medicine
 * Keith Null (born 1985), American football player
 * Luke Null (born 1990), American actor and comedian