Grant was a generous benefactor, and it was estimated that over his lifetime he gifted more than £750,000 of his own money, often anonymously. In 1923 he gave a permanent
endowment of £100,000 to assist the
British government in reconstituting
The Advocates Library and from it establish the
National Library of Scotland.
Lord Macmillan, the Chairman of the National Library Committee, said that when Grant's banker handed him the cheque for the endowment it was signed but the amount left blank for Macmillan to complete himself. Grant later made a further contribution of £100,000 to assist with the building of the Library. He made many donations for developments in his home town of Forres including gifting four windows for the baptistry of Forres Parish Church, designed by Scottish stained glass window artist
Douglas Strachan, a new motorised fire engine, and the town's park, Grant Park, named in his honour. He made an interest free loan of £26,000 to the town of Nairn for the town's harbour scheme, and a £5,000 gift for the reconstruction of the public baths. He also made contributions towards developments in
Lossiemouth, in particular in support of Lossiemouth golf course. He supported the
University of Edinburgh and gave £50,000 to help clear debts incurred as a result of building development. He gave two gifts of £25,000 to support the building of the
University's geology department at Drummond Street. He was one of the main contributors towards the financing of
National War Memorial at
Edinburgh Castle, and gave the
Palace of Holyrood a 4,000 piece silver banqueting service, linen, cutlery and glassware estimated at a cost of £10,000. Recognising the burden of debt incurred by the UK as a result of
World War I, Grant waived, for 5 years, the interest on the £100,000 of war stock that McVitie's had invested in, netting the Government a saving estimated at £25,000. One of his anonymous donations, revealed in
Lord Macmillan's eulogy for him, was his support of the publication of Sir
Walter Scott's
letters. In supporting retired grocers, he made a donation of £5,000 to the
Benevolence Fund of the Scottish Federation of Grocers and Provision Merchants' Association. == Personal life ==