John Francis Croker Stewart was born at 60 Tyrone Street in Belfast, Ireland on 2 September 1881. Coming from a Roman Catholic family, he was the son of John Stewart, a porter, and Margaret Cassidy. 

He was married in St Patrick’s Church, Belfast on 25 December 1910 to Sarah Larmour (b. circa 1879), an illiterate mill worker, and both gave their address as 45 Tyrone Street in the city. They appeared at the same address on the 1911 census and John was described as a marine fireman. It appears that they would have no children.

Stewart’s ship prior to Titanic had been the Olympic. He joined Titanic at Belfast for the delivery trip to Southampton where he then disembarked.

John Stewart continued to work at sea into at least the 1920s but what became of he and his wife remains unclear¹.