Robert Knight was born around 1871 in County Antrim, Ireland.
He was the son of William Knight and Jane Briggs and he was apprenticed as an engineer. He joined the Harland & Wolff Shipyard in 1891 and worked as a leading hand fitter.
He was married in Belfast in 1894 to Sarah McEvoy (b. 1870), a native of Scotland, and the couple had four children: Jane (b. 1897), Robert (b. 1898), Joseph McEvoy (b. 1900) and William (b. 1904).
The family appear on the 1901 census of Ireland living at 16 Tasmania Street off the Shankill Road in West Belfast. By the time of the 1911 census they had moved to 2 Yarrow Street in Clifton, North Belfast. On both occasions Robert was described as an engine fitter. He was a Freemason and was attached to the Hertford Lodge.
Robert was one of the nine-strong "guarantee group" of Harland and Wolff employees chosen to oversee the smooth running of the Titanic's maiden voyage. He, like the rest of his counterparts, died in the sinking. His body, if recovered, was never identified.