Complex
Complex commonly refers to:

Complexity, the behaviour of a system whose components interact in multiple ways so possible interactions are difficult to describe
Complex system, a system composed of many components which may interact with each other
Complex (psychology), a core pattern of emotions etc. in the personal unconscious organized around a common theme such as power or statusComplex may also refer to:

Arts, entertainment and media
Complex (English band), formed in 1968, and their 1971 album Complex
Complex (band), a Japanese rock band
Complex (album), by Montaigne, 2019, and its title track
Complex (EP), by Rifle Sport, 1985
"Complex" (song), by Gary Numan, 1979
"Complex", a song by Katie Gregson-MacLeod, 2022
"Complex" a song by Be'O and Zico, 2022
Complex Networks, publisher of the now-only-online magazine Complex

Biology
Protein–ligand complex, a complex of a protein bound with a ligand
Exosome complex, a multi-protein intracellular complex
Protein complex, a group of two or more associated polypeptide chains
Species complex, a cluster of very similar species difficult to delimit
Pre-Bötzinger complex, a cluster of interneurons in the ventral respiratory group of the medulla of the brainstem

Chemistry
Coordination complex, a central atom or ion and a surrounding array of bound molecules or ions
Chelate complex, a coordination complex with more than one bond

Mathematics
Complex number, an extension of real numbers obtained by adjoining imaginary numbers
Complex polytope, a generalization of a polytope in a complex Hilbert space
Complex analysis, the study of functions of complex numbers
Complex, an element of a field of sets
Chain complex, an algebraic structure
Simplicial complex, a kind of topological space
CW complex, a kind of topological space
Line complex, a 3-dimensional family of lines in space

Geology
Complex (geology), a unit of rocks composed of rocks of two or three types
Complex crater, a type of large impact crater morphology
Volcanic complex, a group of volcanoes
Complex volcano, a volcano of mixed form
Accretionary complex, a fossil accretionary wedge

Other uses
Building complex, a group of inter-related buildings
Housing complex, specifically residential
Market complex, group of stores or business firms in a marketplace having common walkway(s), usually enoclosedwithin a boundary  under r situated under oone roof
UCL Centre for Mathematics and Physics in the Life Sciences and Experimental Biology (CoMPLEX), part of UCL Faculty of Mathematical and Physical Sciences, London, UK

See also
All pages with titles beginning with Complex
All pages with titles containing Complex
Complexity (disambiguation)
Complexity theory (disambiguation)
Military–industrial complex