John William Marriott was born in early 1891 in Kentish Town, London, England and he was baptised on March 1 of that year. He was the son of George Henry Marriott (b. 1850) and Sarah Ann Dicks (b. 1852), natives of Hull, Yorkshire and London respectively who had married in London in 1873, going on to have a total of 12 children, 4 of whom did not live past infancy.

On the 1891 census John, his parents and five siblings are listed as living at 11 Severton Street, Kentish Town, London. His father is listed as a blacking maker (a boot polish maker) and his siblings here are listed as: Mary (b. 1876), Florence (b. 1879), Alice (b. 1881), Samuel (b. 1887) and Nellie (b. 1888). His sister Nellie would go on to marry Titanic crewman George Alfred Levett.

On the 1901 census the family have shifted to a different address, 11 Raglan (?) Street In Kentish Town and another child is present, Elsie (b.1895). Another move took place by the time of the 1911 census with the Marriotts now residing at 5 Slingley Cottages, Brunswick Park Road, New Southgate, London. Another sister Emma (b.1876) is now residing with them. By this time John Marriott is described as an unmarried clerk.
John Marriott signed onto the Titanic in Southampton on 4 April 1912. He gave his address as 7 Chilworth Road (the address of his brother-in-law George Alfred Levett). His last ship had been the Olympic. As an assistant pantry steward he received monthly wages of £3 15s.

Marriott wrote to his friend Reg Light in February: "I hope if you go on the boats you will be a bit luckier than I have been; anyway, I shall no doubt see you before you make up your mind to go to sea. What price the ------? Don't you think it is a doomed ship [the Olympic]? She lost one of her propeller blades this trip, and she's gone to Belfast for repairs again, so there has been something happening every trip. I think she is going down next trip. Really, I feel half scared to go on her next trip, but I think I will take a chance and do one more trip in her, and then stand by for the new boat Titanic. Perhaps that one might be more fortunate." Western Independant, 21 April 1912

John Marriott was lost in the Titanic disaster. 

His body recovered by the MacKay-Bennett and he was buried at Fairview Lawn Cemetery, Halifax, N.S. on 8 May 1912.

John's father and mother both died in Barnet, Middlesex in 1940 and 1943 respectively.