A complex is a whole that comprehends a number of parts, especially one with interconnected or mutually related parts. It may refer to:

• In chemistry, a complex, also called a coordination compound or metal complex, is a structure consisting of a central atom or molecule weakly connected to surrounding atoms or molecules.

• In psychology, a complex is a group of mental factors that are unconsciously associated by the individual with a particular subject and influence the individual's attitude and behavior.

In mathematics:

• A complex number is a number with a real part and an imaginary part, of the form a + ib, where a and b are real numbers and i is the imaginary number.

• A complex system is a system comprised of interconnected simple parts that exhibits a high degree of computational complexity from which emerges a higher order behavior.

• A complex is an element of a complex algebra or field of sets.

• A simplicial complex is a kind of topological space that can be divided into fully adjacent triangles, or more generally, into simplices.

• A CW complex, or closure-finite weak complex, is a kind of topological space, a generalization of the simplicial complex.

Kompleks | Komplex | Complejo | Complexe | Complex