Arnott, Sir Lauriston John (1890–1958), soldier, newspaper proprietor, and philanthropist, was born 27 November 1890, second (and eldest surviving) son of Sir John Alexander Arnott (d. 1940), 2nd baronet, and his wife Caroline Sydney, eldest daughter of Sir Frederick Martin Williams, MP, of Tregullow, Cornwall. The family lived at Woodlands, Cork, and 12 Merrion Square, Dublin. Lauriston Arnott was educated at Wellington College and at the Royal Military Academy, Woolwich, receiving his commission in 1910. He served in 3rd Bn, Royal Irish Rifles, during the first world war, reaching the rank of captain, and was twice wounded in action. In 1919 he returned to Dublin and became a director of the family-controlled Irish Times; he was managing director (1940–54) in name, but this was in effect a sinecure.
A keen sportsman, he served for many years as chairman of the Phoenix Park Race Club (which controlled another family concern, the Phoenix Park racecourse) and was chairman and president of the Leinster Golfer's Alliance. His other major interest was philanthropy: he served as a member of the board of the National Children's Hospital, Harcourt St., Dublin, and as a member, chairman (1947–9), honorary treasurer, and vice-president of the board of management of the Adelaide Hospital, Dublin (1942–58). In his mother's footsteps, he worked on behalf of ex-servicemen, being an active member of the council of the Help Society and honorary general secretary of the Lord Roberts workshop in Dublin. He was a grand deacon of the grand lodge of freemasons of Ireland and an official of the Society for the Prevention of Cruelty to Animals in north Co. Dublin. During the second world war he served as a Local Security Force company commander at Howth. Asked how he reconciled his former career in the British army with his role as an officer in the LSF, he replied, ‘My house out in Shearwater in Howth, that's my home . . . If I saw a British Tommy walking across my meadows, I'd simply have to shoot the bugger, wouldn't I?’ He died 2 July 1958 in Dublin, unmarried.