Lieutenant General Sir Oliver William Hargreaves Leese, 3rd Baronet, KCB, CBE, DSO (27 October 1894 – 22 January 1978) was a senior British Army officer who saw distinguished active service during both the world wars.

Leese was wounded for the third time during the Somme offensive in September 1916,[12] an action in which he was mentioned in dispatches and awarded the Distinguished Service Order (DSO).

[25] Shortly after his arrival, he assumed command of the hastily raised 20th Independent Infantry Brigade (Guards), which was to participate in the ultimately doomed Norwegian campaign although this did not happen.

Due to the German Army's invasion of Western Europe, which began on 10 May, Leese received a signal ordering him to France and to report to General Lord Gort, Commander-in-Chief (C-in-C) of the British Expeditionary Force.

[25] Events moved rapidly and GHQ relocated several times, eventually arriving at Last Panne, Belgium, within the Dunkirk perimeter, on 26 May.

Over the next few days, the staff worked frantically to oversee the withdrawal and evacuation of the BEF back to the United Kingdom, following largely the same plan that Leese had designed.

[25] Throughout the campaign, Leese was "a model of cool, unruffled fortitude during the retreat to Dunkirk" and who "more than anyone, imposed some order on the BEF's withdrawal and evacuation" while booming with confidence.

[25] On 30 December 1940, he was again promoted to the acting rank of major general[28] and given command of the West Sussex County Division that also included the 29th Brigade.

[30] "A forceful personality, Leese proved extremely energetic in getting what he wanted from the War Office and then drove his men hard to create a thoroughly well organised division within a relatively short time.

[32][26] In September 1942 Leese received new and unexpected orders and was sent to Egypt at the request of Lieutenant General Bernard Montgomery, the newly appointed commander of the British Eighth Army in the Western Desert.

[30] Leese commanded XXX Corps during the Second Battle of El Alamein and for the rest of the North African campaign, which ended in Tunis in May 1943, and was mentioned in dispatches for his services.

[40] In late September 1944, he was appointed Commander-in-Chief (C-in-C) of the Eleventh Army Group, based in India and directing operations in Burma, although he was not able to assume command until November by which time it had been renamed Allied Land Forces, South-East Asia (ALFSEA).

"[41] ALFSEA fought a successful campaign in Burma culminating with the recapture of Rangoon in early May 1945, it having been lost in 1942 to the Japanese advance at the time.

[42] Leese believed that Slim was very tired, considering his years of service fighting in Burma and having asked for leave once Rangoon had been taken, and proposed that he should be replaced by Lieutenant General Philip Christison.

The latter was selected as the potential replacement to Slim, due to his experience in amphibious warfare that would be well suited for the next ALFSEA offensive that included a seaborne landing to recapture British Malaya.

As a result, Leese chose Slim to command the new Twelfth Army, to deal with the less demanding task of mopping up remnant Japanese forces in Burma.

[44] In fact, Slim reacted by telling his staff he had been sacked and wrote to Leese and General Sir Claude Auchinleck, the Commander-in-Chief India, to say he would refuse the new post and resign from the army in protest.

Following the amputation of his right leg in 1973, Leese, a widower for the final years of his life after his wife Margaret died in 1965,[47] moved to Wales into a house called Dolwen at Llanrhaeadr-ym-Mochnant, near Oswestry.