Lieutenant General Achates Ernst Wilhelm af Klercker (28 December 1881 – 18 May 1955) was a senior Swedish Army officer.

[2] af Klercker was commissioned as an officer in 1902 and assigned to the 2nd Life Grenadier Regiment as underlöjtnant.

As head of the General Staff's International Department from 1926 to 1930, he studied certain military conditions abroad.

[3] He was then commanding officer of the 1st Army Division (I. arméfördelningen) from 1937 to 1942 and of the I Military District from 1942 to 1947. af Klercker was promoted to Lieutenant General in the reserve of the General Staff on 1 March 1947 and left active service on 1 April 1947.

[1] On 12 October 1907 in Hakarp, Jönköping he married Anna Ingegerd Maria Tham (10 April 1887 in Hakarp – 16 November 1963 in Helsingborg), the daughter of Gustaf Wilhelm Sebastian Tham and Julia Elisabet Louise Reuterskiöld.