AEC is a TLA which can refer to several different things:

• The United States Atomic Energy Commission, a civilian organization that oversaw development of atomic science and technology from 1946 to 1974.
• The Australian Electoral Commission, which organises and supervises elections and voter enrolment in Australian federal elections.
• The Associated Equipment Company, a major United Kingdom bus manufacturer from 1912 until 1979.
• Architecture, Engineering and Construction, a method of organizing resources involving all three aspects of civil, mechanical and building design.