Wilson returned from Australia to fight with his regiment during the Second Boer War and was appointed commander of the 1st Battalion after the Battle of Magersfontein in 1899. He served under Sir John Maxwell in the Sinai and Palestine campaign (World War I) as General Officer Commanding Indian Expeditionary Force E, Canal Defences and was mentioned in dispatches whilst commanding the Suez Canal defences against the Turkish attack through 1915–1916. He was also appointed KCB at around this time.