A domain is a geographic area controlled by a single person or organization. Domain may also refer to:

• Demesne, in English common law and other Medieval European contexts, lands directly managed by their holder rather than being delegated to subordinate managers
• Domaine, a large parcel of land under single ownership, which would historically generate income for its owner.
• Eminent domain, the right of a government to appropriate another person's property for public use
• Private domain / Public domain, places defined under Jewish law where it is either permitted or forbidden to move objects on the Sabbath day
• Public domain, creative work to which no exclusive intellectual property rights apply
• Territory (subdivision), a non-sovereign geographic area which has come under the authority of another government

• Domain (biology), a taxonomic subdivision larger than a kingdom
• Domain of discourse, the collection of entities of interest in logical analysis
• High-field domain (physics) in semiconductors, also called Böer domain
• Knowledge domain, knowledge within a certain discipline, often formalized as a terminology
• Magnetic domain (physics), a region within a magnetic material which has uniform magnetization
• Protein domain (biology), a part of a protein that can exist independently of the rest of the protein chain
• Social domain, a concept in sociology

• Domain (mathematical analysis), an open connected set
• Domain (ring theory), a non-trivial ring without left or right nonzero zero divisors
  • Integral domain, a non-trivial commutative ring without nonzero zero divisors
    • Atomic domain, an integral domain in which every nonzero non-unit is a finite product of irreducible elements
    • Bézout domain, an integral domain in which the sum of two principal ideals is again a principal ideal
    • Euclidean domain, an integral domain which allows a suitable generalization of the Euclidean algorithm
    • Dedekind domain, an integral domain in which every nonzero proper ideal factors into a product of prime ideals
    • GCD domain, an integral domain in which every two non-zero elements have a greatest common divisor
    • Principal ideal domain, an integral domain in which every ideal is principal
    • Unique factorization domain, an integral domain in which every non-zero element can be written as a product of irreducible elements in essentially a unique way
• Domain of a function, the set of input values for which the (total) function is defined
  • Domain of definition of a partial function
  • Natural domain of a partial function
  • Domain of holomorphy of a function
• Domain of an algebraic structure, the set on which the algebraic structure is defined
• Domain of discourse, the set of entities over which logic variables may range
• Domain theory, the study of certain subsets of continuous lattices that provided the first denotational semantics of the lambda calculus
• Frequency domain, the analysis of mathematical functions with respect to frequency, rather than time
• Fundamental domain, subset of a space that contains exactly one point from each orbit of the action of a symmetry group
• Time domain, the analysis of mathematical functions with respect to time

• Administrative domain
• Broadcast domain, in computer networking, a group of special-purpose addresses to receive network announcements
• Collision domain
• Domain (software engineering), a field of study that defines a set of common requirements, terminology, and functionality for any software program constructed to solve a problem in a given field
  • Application domain, a mechanism used within a Common Language Infrastructure to isolate executed software applications from one another
  • Programming domain, a set of programming languages or programming environments that were engineered specifically for a particular domain (software engineering)
• Network domain, a named grouping of hosts and servers with managed login, access to resources, and permissions.
  • Domain name, a label that identifies a realm of administrative autonomy, authority, or control within the Internet
• Attribute domain, the set of values allowed in an attribute.

• The Domain (Austin, Texas), a shopping mall in Austin, Texas, United States
• Domain (Hong Kong shopping centre), a shopping mall in Yau Tong, Kowloon, Hong Kong
• Domain, Manitoba, a hamlet in Manitoba, Canada
• Domain Precinct, a part of South Yarra in Melbourne, Victoria, Australia

• The Domain, Sydney, a large open space near the central business district of Sydney
• Kings Domain, Melbourne, Victoria
• Queens Domain, Hobart, Tasmania

• Auckland Domain: a large inner-city park in Auckland
• One Tree Hill Domain in Auckland
• Mount Eden Domain in Auckland
• Mount Smart Domain in Auckland
• Mangere Domain in Mangere
• Hamilton Lake Domain in Hamilton
• Taumarunui Domain in Taumarunui
• Ashburton Domain in Canterbury
• Ocean Beach Domain in Dunedin

• Domain (2009 film), a French film
• Domain (2016 film), an American film
• The Domain (film), a 2019 Portuguese film

• "Domain", track by John Carpenter from Lost Themes
• "Domain", a song by KSI from the 2020 album Dissimulation

• Domain, or battlespace, a concept in military operations dividing operating environments into defined components
• Domain Group, an Australian real estate marketing portal, owner of the brand domain.com.au and others

• Dominion (disambiguation)