Mr John Richard McMullin was born in Lymington, Hampshire, England during the second quarter of 1876.

He was the son of John McMullin (b. circa 1845), a coastguard, and Mary Ann “Marion” Coughlan (b. circa 1845) who were married in 1873. His father was a native of Dublin, Ireland whilst his mother was from Southampton, the daughter of Irish immigrants from Cork and Kerry. He had three siblings: Katherine Bertha May (December 1874-1944), William Albert Sydney (March 1878-1947) and Ernest Fairfax Sutherland Victor (July 1887-1955).

McMullin first appears on the 1881 census living at the Coastguard Cottage in Binsted, Hampshire where his father was a Coastguard for the Royal Navy. By the time the 1891 census was taken John was visiting his uncle and his family at 545 Old Kent Road, Camberwell, London but is totally absent for the 1901 census, already working at sea at that point. 

When McMullin first went to sea is not known, although he is known to have served as a waiter aboard Pretoria as soon as 1896. By the early 1900s he was shown working as a waiter aboard Moor, later switching amongst Armadale Castle, Kildonan Castle and Kinfauns Castle between July 1901 and March 1910 as boots steward or bedroom steward.

On the 1911 census he is shown with his family, then at 120 St Mary's Road, Southampton, his father having retired. John was then described as an unmarried ship's steward. 

John initially signed-on to the Titanic in Belfast for her delivery trip to Southampton. When he signed-on again on 6 April 1912 for the maiden voyage he gave his address as 120 St. Mary's Road, Southampton. His previous ship had been the Olympic and as a saloon steward he received monthly wages of £3, 15s.

John McMullin died in the sinking and his body, if recovered, was never identified. 

John’s father passed away only weeks after his loss; his mother remained in Southampton where she died in 1917.

His sister Bertha spent a portion of her later life in a lunatic asylum in Droxford, Hampshire where she passed away in 1944.