Cluster(s) may refer to:

• Cluster (spacecraft), constellation of four European Space Agency spacecraft
• Cluster II (spacecraft), a European Space Agency mission to study the magnetosphere
• Asteroid cluster, a small asteroid family
• Galaxy cluster, large gravitationally bound groups of galaxies, or groups of groups of galaxies
• Supercluster, the largest gravitationally bound objects in the universe, composed of many galaxy clusters
• Star cluster
  • Globular cluster, a spherical collection of stars whose orbit is either partially or completely in the halo of the parent galaxy
  • Open cluster, a spherical collection of stars that orbits a galaxy in the galactic plane

• Cancer cluster, in biomedicine, an occurrence of a greater-than-expected number of cancer cases
• Cluster headache, a neurological disease that involves an immense degree of pain
• Cluster of differentiation, protocol used for the identification and investigation of cell surface molecules present on white blood cells
• Winter cluster, in beekeeping, a well-defined cluster of honey bees in cold temperatures
• Disease cluster, a grouping of cases of disease
• Gene cluster, a group of genes (or proteins, or metabolites) whose expression or concentration is similar across a range of conditions
• Cluster of microorganisms, as in a colony

• Cluster chemistry, an array of bound atoms intermediate in character between a molecule and a solid

• Computer cluster, a set of computers that work together
• Data cluster, a group of disk sectors used in a File Allocation Table

• Business cluster, a geographic cluster of competitive businesses

• Cluster theory, a theory that states concentrating industries in specific regions creates several advantages

• CLUSTER, the Consortium Linking Universities of Science and Technology for Education and Research (a collection of twelve European universities which focus on science and engineering)

• Cluster bomb, a type of air-dropped or ground-launched shells
• Instrument cluster of an automobile
• A bicycle cogset, either a freewheel, or cassette
• The set of tubes attached to a cow's teats for automatic milking

• Consonant cluster, a group of consonants which have no intervening vowel
• Language cluster or dialect cluster, a geographic distribution of languages

• Cluster analysis, a set of techniques for grouping a set of objects based on intrinsic similarities
• Cluster sampling, a sampling technique used when "natural" groupings are evident in a statistical population
• Cluster graph, in graph theory, a disjoint union of complete graphs
• Clusterable graph, in balance theory
• Cluster algebra, a class of commutative rings used in representation theory
• Cluster expansion, a technique in statistical mechanics and quantum field theory

• Cluster (physics), a small group of atoms or molecules

• Cluster home, a type of housing development
• Research-intensive cluster, a region with a high density of research-oriented organizations
• Urban agglomeration, a cluster concept in urban development (a human settlement with a high population density and an infrastructure of built environment)

• Khandha, a Buddhist concept of five material and mental factors that take part in the rise of craving and clinging
• Proper name (philosophy), a cluster of propositions that in combination pick out a unique referent

• Tone cluster, a musical chord comprising at least three consecutive tones in a scale
• Cluster (album), the 1971 eponymous album by the band Cluster
• Cluster (band), a German electronic group
• "Cluster", a track from the album Ben Bu Sarkiyi Sana Yazdim by Cem Adrian
• "Cluster", a song by P-Model from the album Big Body
• Cluster One, the first track on Pink Floyd's 1994 album The Division Bell
• "Cluster", an extended play by the pop-punk band Waterparks

• Cluster (novels) by Piers Anthony
• Cluster, a poetry collection by Souvankham Thammavongsa
• The Cluster, a character from the TV series Steven Universe

• Cluster, Pleasants County, West Virginia
• Cluster diagram, general type of diagram, which represents some kind of cluster
• Clusterfuck or cluster, slang term for a messy situation, arising in the US Marine Corps
• Clusters School of Digital Arts, an animation and visual effects training school

• Clustering (disambiguation)