# Separation

Separation may refer to:

## Films

* Separation (1967 film), a British feature film written by and starring Jane Arden and directed by Jack Bond
* La Séparation, 1994 French film
* A Separation, 2011 Iranian film
* Separation (2013 film), an American thriller film starring Sarah Manninen
* Separation (2021 film), an American horror film

## Literature

* The Separation (Bury Novel), an 1830 novel by Lady Charlotte Bury
* The Separation (Priest novel), a 2002 novel by Christopher Priest
* The Separation (Applegate novel), a 1999 novel in the Animorphs series by K.A. Applegate
* Separation, a 1976 Canadian political novel by Richard Rohmer

## Music

* Separation, a 2011 album by Balance and Composure
* Separation (EP), a 2006 EP by Halou
* Separations (album), a 1992 album by British alternative rock band Pulp
* Separation mastering, in music recording

## Law and politics

* Marital separation, when a married couple ceases living together without a divorce
** Legal separation, a legal status where married couples may disentangle their finances without divorce
* Nonconformity to the world (separation from the world), a belief among some Protestant religious groups that the members of a church should be separate from "the world"
* Political separation (separatism), advocacy of a state of cultural, ethnic, tribal, religious, racial, governmental or gender separation from the larger group
* Separation of church and state, the idea that religion and government functions should be separate

## Mathematics and science

* Separation (behavior), the behavior of flocking animals to stand off from their neighbours
* Separation (statistics), a problem encountered in fitting models for categorical outcomes
* Flow separation, separation of a fluid boundary layer from the surface of a solid body moving relative to the fluid
* Intertemporal portfolio choice#Time-independent decisions, where in some contexts portfolio choices for many periods can be made separately
* Separated sets, related concept in topology, two sets disjoint from the other's closure
* Separation axiom, concepts in the area of mathematics called topology
* Separation of concerns, in computer science (and problem-solving in general)
* Separation of variables, in mathematics to solve certain (separable) differential equations
* Separation principle, in control theory
* Separation process, in chemistry
* Separation theorem (disambiguation): several different theorems related to separation, in different scientific disciplines, for example:
** Mutual fund separation theorem, allowing a portfolio optimization problem to be separated into smaller problems
* Point-pair separation, in an order two pairs of points may or may not separate each other

## Other uses

* Separation (aeronautics), rules to minimise the risk of collision between aircraft in flight
* Separation (United States military), the process by which a service member leaves active duty
* Separation anxiety disorder, an anxiety disorder in which an individual experiences excessive anxiety regarding separation from home and/or from people to whom the individual has a strong emotional attachment
* Racial separation, the separation of different racial groups in daily life
* Six degrees of separation, the idea that everyone is on average approximately six steps away, by way of introduction, from any other person on earth
* Curdling of an emulsion in cookery is called "separation"