John Arthur Prideaux (known as Jack) was born in Southampton, Hampshire on 24 April 1888 at a house in Victoria Road, Woolston. He was the son of John Davey Prideaux and Annie Elizabeth (formerly Slade).

His father, originally from Teignmouth, Devon was, at the time of his son's birth described as an eating housekeeper. This job and his marriage to Annie seem to have been quite short-lived as within 3 years he is shown on the 1891 census as living in Sussex, unmarried and working as a head waiter.

At some point Jack moved with his mother to live in Bournemouth and by the time of the 1901 census his mother was described as a widow, and he aged 13, was an office boy at a firm of decorators. Their Bournemouth address in 1912 was 23 Cotlands Road and newspaper reports shortly following the disaster revealed that Jack was well known as one of the joint secretaries of the Bournemouth Wanderers Football Club.

He signed on to the Titanic as a third class steward at Southampton on 4 April 1912 (his first ship) on a monthly wage of £3 15s. He was also to act as a purser's clerk.  Family members watched the Titanic sail by from their home on the Isle of Wight.

A promising artist, a family story suggests that Jack intended to jump ship after arrival in New York and seek his fortune in the United States.

He was lost in the sinking 9 days before his 25th birthday and his body was not amongst those subsequently recovered or identified.

Shortly after the tragedy, two Dorset newspapers carried items about Jack as did the 25 April 1912 edition of the Newton Abbot Western Guardian, a Devon newspaper. The item relating to the village of Shaldon in that newspaper ran as follows

PC Prideaux the village constable, has lost a nephew, a promising young fellow who was clerk to the purser on the Titanic, he was a young man of fine physique and was the only son of a widow who resides in Hampshire.

The police constable, Jack’s uncle, was William Arthur Prideaux who was born in Devon in 1874. (William was the second youngest of 8 children and a younger brother of Jack’s father.)