James Muil Smith was born in Elgin, Morayshire, Scotland on 17 February 1873.

He was the son of Peter Smith (1844-1917), a dairyman, and Catherine Muil (1845-1922). Both his parents were native to Morayshire, his father to Edinkillie and his mother to Elgin and they had married on 22 March 1867. He had three known siblings: Catherine Shearer (b. 1867), Helen Ross (b. 1868) and Jane Ann (b. 1870).

When James appears on the 1881 census he is listed at the home of his grandparents James and Jessie Smith at 241 High Street, Elgin. His parents and siblings are listed elsewhere at 234 Winchesters Close, Elgin. The family would later moved to 91 High Street in Elgin and would be listed there on the 1891 census. James was then described as an engineer.

He served his apprenticeship with Messrs. J. S. Souter of Elgin and later settled in Thurnham Street, Liverpool and served at sea with the Anchor Line of Glasgow and a number of coasting companies prior to obtaining his certificates of competency. Prior to joining the White Star Line in 1906 he sailed with Union Castle Line and Red Star Line.

James was married in Southampton in 1908 to Hannah Davidson Smith (b. 28 May 1879 in Melbourne, Derbyshire) and the couple had one son, Ian James (b. 1910). At the time he was serving aboard the Majestic before "standing by" the Titanic during her construction.

When he signed on to the Titanic, on 6 April 1912, James gave his address as "Cawdor," Millars Road, Itchen, (Southampton). He stated his previous ship had been the Majestic and as Junior 4th Engineer he could expect monthly wages of £13, 10s.

James Smith died in the sinking. His body, if recovered, was never identified.

His widow and son benefitted from the Titanic Relief Fund. James' son Ian never reached his tenth birthday and died in late 1919. His widow Hannah never remarried and remained living in Southampton, later living at 558 Portswood Road. She died in hospital on 19 October 1953.

James Muil Smith is remembered on his wife's headstone in St. Mary Extra Cemetery Southampton (section C 17, plot 32), he is also remembered on his family headstone in Elgin Cemetery, Moray, Scotland, (section Elgin East, Lair 354F+355F).