Kenneth John Macksey MC (1 July 1923 – 30 November 2005) was a British author and historian who specialized in military history and military biography, particularly of the Second World War. Macksey was commissioned in the Royal Armoured Corps and served during the Second World War (winning a Military Cross under the command of Percy Hobart). Macksey later wrote the (authoritative) biography of Hobart. Macksey gained a permanent commission in 1946, was transferred to the Royal Tank Regiment in 1947, reached the rank of major in 1957 and retired from the Army in 1968.
Amongst many other books, Macksey wrote two volumes of alternate history, one, entitled Invasion, dealt with a successful invasion of England by Germany in 1940 and the other describing a NATO–Warsaw Pact clash in the late 1980s. The latter book, First Clash, was done under contract to the Canadian Forces and focuses on the Canadian role in such a conflict. He was an editor and contributor to Greenhill's Alternate Decisions series since 1995.
- The Shadow of Vimy Ridge. W. Kimber. 1965. OCLC 1601233.
- Guderian: Creator of the Blitzkrieg. Stein and Day. 1975. OCLC 3100080.
- Armoured Crusader: a biography of Major-General Sir Percy Hobart. London: Hutchinson (publisher). 1967. ISBN 0-09-084950-7.
- Africa Korps. New York: Ballantine Books. 1968. ISBN 0-345-21687-3.
- Kesselring: German master strategist of the Second World War. London: Greenhill Books. 2000 . ISBN 1-85367-422-2.
- Invasion: the alternate history of the German invasion of England July 1940. Ashcroft: Wren's Park Publishing. 2001 . ISBN 0-905778-79-0.
- Guderian: Panzer General. London: Greenhill Books. 1992. ISBN 1-85367-059-6.
- Why the Germans lose at war: the myth of German military superiority. London: Greenhill Books. 1999 . ISBN 1-85367-383-8.
- Military Errors of World War II. London: Arms and Armour Press. 1987. ISBN 0-85368-830-3.
- Rommel: battles and campaigns. London: Arms and Armour Press. 1979. ISBN 0-85368-232-1.
- The Tanks: a History of the Royal Tank Regiment, 1945-1975. London: Arms and Armour Press. 1979. ISBN 0853682933.
- Anatomy of a Battle. New York: Stein and Day. 1974. ISBN 0-8128-1650-1.
- Panzer Division, the mailed fist. New York: Ballantine Books. 1968. ISBN 0-345-24992-5.
- Beda Fomm: Classic Victory. New York: Ballantine Books. 1971. ISBN 0-345-02434-6.
- with William Woodhouse (1991). The Penguin encyclopedia of modern warfare: 1850 to the present day. London: Viking Books. ISBN 0-670-82698-7.
- First Clash: Combat close-up in World War Three. USA: Sterling Publishing. 1985. ISBN 978-0-7737-2060-2.
- Commissioning date 23 April 1944
- MC awarded 21 December 1944
- Dated 5 October 1946
- Dated 3 January 1947
- Promotion date 1 July 1957
- Retirement date 3 August 1968
- Invasion (1980)
- First Clash (1985)
- Schmunk, Robert B. Tsouras, Peter G.; Kenneth Macksey; Jonathan North (eds.)., eds. "Greenhill's Alternate Decisions". Uchronia: The Alternate History List. Retrieved 20 December 2012.