Remaining in the army during the interwar period, Wilson served in Ireland with the 2nd Battalion, KRRC during the Anglo Irish War. He married in 1922 and attended the Staff College, Camberley, from 1928 to 1929. Among his fellow students there included several who would become general officers during the Second World War, such as Gerald Templer, John Harding, Richard McCreery, Gerard Bucknall, Charles Miller, Alexander Galloway, Alexander Cameron, Philip Gregson-Ellis, Charles Murison, Claude Nicholson, William Holmes, I. S. O. Playfair and Gordon MacMillan. After graduating from Camberley Wilson served briefly again with the 2nd Battalion, KRRC before being sent to the War Office, where he served as a General staff Officer Grade 3 (GSO3) from January 1931 until March 1932.