Hugh Dormer was the younger son of Captain Kenelm Dormer and his wife, Josephine Sarah Toohey, who was an Australian.

In December 1919, she took both of her sons to visit her family in Australia. Some five years later, in February 1924, she took Hugh on a visit to Kenya. It is possible that the family had interests there as she spent time there after 1945 and her other son settled there. Hugh went to Australia with her, again, in 1930.

Hugh was educated at Ampleforth. Cardinal Basil Hume who was a younger pupil at the time, recalled that he was an outstanding head of his House, was a dedicated Catholic and, with high intelligence and love of people, would have very likely become a priest.  When asked if he might have become a successor to the Cardinal as Archbishop of Westminster, Hume said "Perhaps. God's hand is unpredictable, but he would have been as outstanding after the War as he was in it" 

His father died in 1935 and Hugh came up to Christ Church in 1937.

After Sandhurst, he was a subaltern in the Irish Guards. He volunteered for service with the Special Operations Executive (SOE) and on 18 April 1943, was dropped from a Halifax with a party of six, to destroy an oil plant at Le Creusot in France. They were spotted and made their escape to Paris, took a train to Perpignan, and walked across the Pyrenees to Spain and returned to England through Gibraltar.

On 16 August 1943, he led another party to the same target. They were successful in disabling the plant and made the same journey across the Pyrenees to England; but only two out of the six returned.

He went back to his regiment and was killed in Normandy on 31 July 1944.

For his actions with SOE he was awarded the Distinguished Service Order.

He is buried in St. Charles de Percy War Cemetery, Calvados Plot I. C. 9.

He is commemorated in the Royal Military Chapel, Sandhurst and the Memorial Chapel, Ampleforth.

It was created by John Bunting, a former pupil who was a Sculptor and Master of Drawing at Ampleforth. Built between 1957 and 1960 on a hill overlooking Oldstead, on the edge of the North York moors, it is dedicated to old Amplefordians killed in action – Hugh Dormer, D.S.O.; Michael Allmand V.C. and Michael Fenwick; all of whom were killed in the Second World War. Robert Nairac, G.C., was added to that trio when he was killed in 1997 in Armagh.
Hugh Dormer’s Diaries were published in 1974 and the Guards website carries more information on him.