Apportionment is a legal term for distribution or allotment in proper shares.
Apportionment may also refer to: Biology Niche apportionment models of relative species abundance distributions
Law Uniform Apportionment of Tort Responsibility Act, a Uniform Act drafted by the National Conference of Commissioners on Uniform State Laws (NCCUSL) Formulary apportionment, a method of allocating corporate taxation between jurisdictions
Mathematics Fair division, in game theory Apportionment paradox, various paradoxical proofs in political apportionment
Business Apportionment of overhead costs across different cost centres
Politics and government Apportionment (politics), the process of allocating the power of a set of constituent voters among their political representatives Biproportional apportionment Apportionment of votes in a proposed United Nations Parliamentary Assembly
Europe Apportionment in the European Parliament National apportionment of MP seats in the Riksdag (Swedish national legislature)
United States United States congressional apportionment Apportionment (OMB), distribution of US government funds New Jersey Apportionment Commission Ohio Apportionment Board