Born 16 June 1871, the eldest child of Samuel Cookson, MRCS MD St Andrews 1862, of Stafford, and his wife Jane Grace, daughter of Henry Day, FRCP 1879, MRCS 1842, and widow of Mr Gibson. He was educated at Epsom College and at the Middlesex Hospital, where he was Freer Lucas scholar and subsequently house surgeon. He then served as house surgeon at the Bristol General Hospital, and as clinical assistant at the Chelsea Hospital for Women. He settled in practice in his native town of Stafford, becoming surgeon and eventually consulting surgeon to the Staffordshire General Infirmary. He represented the Stafford division of the British Medical Association in London before the Toronto meeting of 1906, at the Sheffield meeting in 1908, and at Belfast in 1909. Cookson married on 10 June 1902 Mary MacIver Percival, second daughter of Thomas Parry Parry-Jones, who survived him but without children. He practised at Taggscroft, Stafford, and retired to Moss-pit House some years before his death, which took place in the Staffordshire General Infirmary on 1 December 1941.