Hall had just finished his schooling when the First World War broke out, during which he served as an infantry and staff officer. He was decorated with the Military Cross and Bar, and rose to the rank of major. After the war he took a shortened degree course at the University of Oxford, and made his first visit to China for a student Christian conference in 1922. After a period as a parish priest in his native Newcastle, he became Bishop of Victoria, Hong Kong in 1932, remaining in Hong Kong until his retirement in 1966. He and his wife then settled in Oxfordshire.
Hall was born on 22 July 1895 in Newcastle, England, the second child (and eldest son) of an Anglican clergyman, Cecil Gallopine Hall, who was then Curate of St Andrew's Newcastle, and his wife Constance Gertrude (née Upcher, herself the daughter of another clergyman). Hall was educated at the Royal Grammar School, Newcastle, and Bromsgrove School.
With the outbreak of the First World War, he joined the Northumberland Fusiliers. He was commissioned as a second lieutenant on 10 December 1914 for service with the 18th (1st Tyneside) Battalion, one of the "Pals battalions" raised as part of Lord Kitchener's New Armies. He was promoted to temporary captain on 1 April 1915. He was transferred to 15th (Nottingham) Battalion, Sherwood Foresters on 9 July 1915, and subsequently to the General List with the same date, having been appointed a staff captain. On 7 June 1916 he was appointed a General Staff Officer, 3rd Grade. On 7 April 1917 he was appointed brigade major, reputedly the youngest in the British Army. He was appointed General Staff Officer, 2nd Grade, with the temporary rank of major (United Kingdom), on 14 October 1918. He relinquished his commission on 16 January 1919. He was awarded the Military Cross in the 1918 New Year Honours, and a Bar to the medal in the 1919 New Year Honours.
After the war, Hall took his degree at Brasenose College, Oxford, on the shortened degree course run in the immediate post-war years. He became a leader of the British Student Christian Movement and was appointed to the national staff in 1920. Hall attended the World's Student Christian Federation conference in Peking in 1922. He became friends with young Chinese Christian leaders, including the evangelist T. Z. Koo (Gu Ziren) and Y. T. Wu, the founder of the Three-Self Patriotic Movement in China.
Ordained deacon in 1920 in Newcastle Cathedral and priest in Southwark Cathedral in 1921 for work with the Student Christian Movement, Hall later became vicar of St Luke's Newcastle upon Tyne.
In 1932 he was appointed Bishop of Victoria, Hong Kong, and then from 1951 of the smaller Diocese of Hong Kong and Macau, retiring in 1966.
Hall was described as a "legendary figure" with a "burning compassion for the less privileged". He emphasized the needs of ordinary people, especially victims of social upheaval. As Bishop of Hong Kong, he advocated for the poor and supported the Chinese revolution. Before World War II, Hall established an orphanage in Tai Po, Hong Kong, which later became the St Christopher’s Home. He was also instrumental in the setting up of the Hong Kong Housing Society. Under his leadership, the Anglican Church became a major partner with the Hong Kong government in provision of social services.
While Bishop of Hong Kong, Hall ordained the first woman priest in the Anglican Communion. The Japanese occupation of Hong Kong and of parts of China had made it impossible for Anglican priests to get to neutral Macau, where there were a number of refugee Anglicans with no priest. Li Tim-Oi had already been made a deaconess in Macau by Hall and had been authorised by him and his assistant to give the sacraments to the Anglicans in these extenuating circumstances. In January 1944, Li travelled through Japanese-occupied territory to meet with Hall in the small town of Xing Xing, as yet unoccupied by the Japanese, where he regularised her administration of the sacraments by ordaining her as a priest. The Archbishop of Canterbury at the time, William Temple, confided to others his conflicting views but he felt compelled to take a public stand against it.
When the war ended in 1945, Li, to avoid controversy, gave up her licence as a priest, though never renounced her ordination. At the provincial synod of the Chung Hua Sheng Kung Hui in Shanghai in 1947, Hall tried but failed to receive retroactive approval in canon law for Li's ordination. In 1948, Hall was awarded the Order of the Brilliant Star with Plaque by Chiang Kai-shek.
Hall retired in 1966 and was succeeded as bishop by Gilbert Baker. Hall would subsequently be recognized throughout Hong Kong and England:References to Hall can be seen around Hong Kong. The Anglican seminary in Hong Kong, Ming Hua Theological College, and one of the student hostels of Chung Chi College, Chinese University of Hong Kong, Ming Hua Tang, are both named after him.
In 1965, the University of Hong Kong awarded him the Doctor of Divinity (honoris causa).
In the 1966 Queen's Birthday Honours, Queen Elizabeth appointed Hall Companion of the Order of St Michael and St George (CMG).
The Bishop Ho Ming Wah Chinese Centre was opened in London in 1987.