Edwin Marsden (26 April 1913^[1] – 30 August 1975) was a British trade unionist and communist activist.

Born in the Openshaw area of Manchester,^[2] Marsden trained as a draughtsman but instead became a steel erector.^[3]

In 1935, Marsden joined the Communist Party of Great Britain (CPGB), radicalised in opposition to the Italian invasion of Abyssinia.^[4] He also joined the Constructional Engineering Union, serving as a site steward for more than thirty years.^[3]

In 1952, Marsden was elected to the executive of the union, representing North West England,^[2] and in 1962 he became the union's full-time organiser for the region,^[5] also representing the union on the executive of the Confederation of Shipbuilding and Engineering Unions.^[2] Meanwhile, he became increasingly prominent in the CPGB, serving on its Lancashire and Cheshire District Committee,^[2] and standing unsuccessfully for the party in the 1963 Manchester Openshaw by-election, and again in the seat in the 1964 and 1966 general elections.^[6] In 1968, he was elected to the party's Executive Committee.^[2]

Marsden was elected as general secretary of the union in 1968.^[3] Three years later it became part of the Amalgamated Union of Engineering Workers, albeit remaining largely autonomous, with Marsden continuing as general secretary of the union's new Construction section.^[7] This gave Marsden increased prominence in the trade union movement, and he was a prominent figure at meetings of the Trades Union Congress.^[2]

Marsden died in 1975, still in office.^[3]