He was the son of Reverend John Charles Boileau Grant MA and Ellen Jemima Clarke Grant of the Manse, 16 Baker Street, Nottingham.
Rev. Grant was born in Grangetown, Scotland, and was minister at St Andrew's Presbyterian Church from 1894 until 1932. He died in Torquay, Devon, in 1942. His wife died aged 40 on 1 January 1900.
Donald was their second son; eight children were named on the three censuses between 1891 and 1911: Ellen Jane Shaw, John Charles Boileau, Mary LC, Donald Patrick Clarke, Elizabeth DG, Ludovick Nairn Carnethy, Allen Roy Stewart and Grace Isobel Kinrara (Grizel).
In 1891 Rev and Mrs Grant were living at the Free Church Manse on Hawthorn Gardens, Loanhead, Midlothian, with their four children, Ellen (6), John (5), Mary (2) and Donald (1) and two female servants.
Rev Grant and his family moved to Nottingham in 1894 where his wife died on 1 January 1900. In 1901 all eight children were living with their father in the Manse on Baker Street. The family had three live-in servants, Elizabeth Burgess (30), the housekeeper/domestic, Florrie Bush (21), the cook and Mabel Smalley (18) a housemaid. The two youngest children, Allen and Grace, were born in Nottingham.
In 1911 only Ellen (26), Donald (21), Ludovic (18), Allan (15) and Grace (14) were living in their father's household. They had only one general domestic servant, Mary Fox (27), and it is likely that Ellen, who had no given occupation, kept house for her father.
Allan served in the war as a captain with the 10th Seaforth Highlanders and was awarded the Military Cross, and John became a Lieutenant in the RAMC; both survived the war.