Cleland was born in Edinburgh the only son of barrister William Lennox Cleland and Henrietta Cleland, née Fullerton, who married in 1816. On leaving school Cleland joined the East India Company as a midshipman aboard Reliance. He left the Company for service with the London and Counties Bank; Reliance was wrecked near Boulogne in November 1842, shortly after. He married Thomas Glen's daughter Elizabeth in 1845 and they went out to China as missionaries. Their first two children, William Lennox and Margaret Henrietta were born in Hong Kong in 1847 and 1848, and son John was born in Canton in 1850. Then Cleland suffered sunstroke, and the family returned to England and settled in Taunton, where George Fullerton Cleland was born in 1852. They then left for South Australia aboard Gloucester, arriving in August 1852, and settled in a prefabricated home brought out from India by Edward Gleeson on a property dubbed "Gleeville", at 1 Dashwood Road, Beaumont. The two older children died in 1854 after suffering scarlet fever followed by dropsy. They had five more children, all boys. Cleland was appointed Registrar of Births, Marriages and Deaths in 1853, and held the position until 1885, when he resigned at the request of the Government, to be replaced by Dr. H. T. Whittell. Elizabeth died on 4 November 1895; he died on 29 November 1901 and was survived by six sons:
G Fullerton Cleland married Amy Giles on 22 January 1878; he was a wine merchant of Adelaide, chairman of Burnside District Council 1887; she was the daughter of merchant Henry Giles. They lived at "Braemar", Mount Lofty.
E Davenport Cleland married Susan Blood Hobbs, née Davies, on 16 January 1879; he married again, to Anne Emily "Annie" Mackinnon on 14 August 1900; he was a journalist then mine manager in Broken Hill then Coolgardie, died in West Perth.
Charles Alexander Cleland married Ethel Mary Dutton on 5 February 1891; he was an Adelaide surveyor; she was daughter of Edward Dutton. They had no children.
E Erskine Cleland married Edith Mary Auld on 12 April 1893; he was a solicitor, then judge; she was only daughter of W. P. Auld; lived on East Terrace, Adelaide, Church Terrace, Walkerville
The Beaumont Clelands were distantly related to Professor Sir John Cleland FRS of University of Glasgow John Cleland, Northern Territory pioneer and hero of the SS Gothenburg shipwreck was not a close relative.
