William George McArthur was born in Bootle, Liverpool, Lancashire on 15 March 1894, the son of William and Emily Jane McArthur (née Arches). The family home was at 22 Elm Drive, Seaforth, Liverpool, Lancashire.
He was employed as Assistant Pastry Cook on the Lusitania in the Stewards' Department and did not survive the sinking. He was aged 21 years.
His body was not recovered and identified, so he is commemorated on the Mercantile Marine War Memorial at Tower Hill, London.
Register of Births, Marriages and Deaths, 1911 English Census, 1901 English Census, Commonwealth War Grave Commission, Cunard Records, PRO BT 334.