John Charles Mabey was born in Freemantle, Hampshire, England on 11 September 1888. He was the son of William John Mabey (1841-1910) and Amelia Frances Jackson (1846-1897), both natives of Eling, Hampshire who had married there in 1863.
John had eleven known siblings, of which he was the youngest: Henry Charles David (b. 1865), William Alfred (b. 1868), Albert (b. 1872), Charles (b. 1873), George (b. 1875), Letitia Florence (b. 1877), Arthur Archibald (b. 1879), Minnie Jane (b. 1880), Edwin Morris (b. 1881), Kathleen Flora (b. 1883) and Ethel Olive (b. 1886). All of the males in this family are believed to have went to sea.
On the 1891 census John and his family are living at 55 Millbrook Road, Millbrook, Hampshire and his father is described as a master mariner. On the 1901 census he is listed as living with his brother William at Fishers Road, Totton, Hampshire, his mother having passed away in 1897 and his father perhaps working at sea. His father would later die in 1910 in Southampton as a result of drowning in the Southampton Water estuary. On the 1911 census John, still unmarried, is living with another brother George at 123 Bevois Valley Road, Southampton and he is listed as a ship's steward.
When he signed-on to the Titanic, on 4 April 1912, he gave his address as 27 Grove Road, (Southampton). His last ship had been the Olympic. As a third class steward he received monthly wages of £3 15s.
Mabey died in the sinking. His body, if recovered, was never identified.
Following the disaster John's eldest brother Henry Charles had a son in 1915 who would be named after him. The younger John Charles would later marry, raise a family and die in Cornwall in 2001.