The Constructional Engineering Union (CEU) was a trade union representing steel erectors and other workers involved in steel construction in the United Kingdom. The union was founded in 1924 as a section of the Iron and Steel Trades Confederation (ISTC). They left the ISTC and became an independent union in 1930. In 1971, the union merged with the Amalgamated Union of Engineering and Foundry Workers to form the Amalgamated Union of Engineering Workers, becoming a largely autonomous section of the new union.