Mr William McCarthy was born in Cork City, Co Cork, Ireland on 7 September 1863 and baptised later that month.

He was the seventh son of a coastguard, John McCarthy, and his wife Catherine, née Cashman (b. circa 1831). 

His known siblings were: Henry Thomas (b. 10 April 1868-1900), Alfred (b. 7 May 1870), May (b. circa 1868) and Catherine (b. circa 1871). Other details about his early life remain vague but it is known that his father died sometime prior to 1901.

His mother and sisters May and Catherine appear on the 1901 census living at 9 Grattan Hill, Cork and on the 1911 census at the same address; William is not present on either record and it can be surmised that he was working at sea on both occasions. Although he was or had been married the identity of his wife remains uncertain.

When he signed on to the Titanic on 6 April 1912, McCarthy gave his address as 9 Grattan Hill Road, Cork, Ireland. His previous ship was the Castlemoor and as an able seaman his wages were £5 per month.

McCarthy survived the disaster in lifeboat 4. His conduct aboard that boat was highly commended by first class passenger Mrs Walter Miller Clark.

Following the disaster, William returned to England aboard the Lapland and was not required to give evidence to either the US or British Inquiries into the sinking.

It is possible he continued working at sea throughout WWI before retiring to his native Cork and taking land-based labouring jobs; he also made a hobby out of creating ornamental anchors from driftwood and shell. He would live at 9 Grattan Hill, Cork for the rest of his life; his mother passed away there from senility and old age on 26 January 1916.

William McCarthy, a widower, died from a heart complaint in Cork District Hospital on 14 January 1932 aged 69. 

McCARTHY (Cork)--On January 14, 1932, William McCarthy of 9, Grattan's Hill, Lower Road, Cork, seventh and only surviving son of the late Mrs and John McCarthy (late Officer of his Majesty's Coast-guards), and grandson of the late John Cashman, Main Street, Whitegate, and one of the surviving crew of the ill-fated Titanic. Deeply regretted by his sisters and relatives. R.I.P. Funeral from St Patrick's Church at 12 o'clock on tomorrow (Sunday), to Inch, Whitegate. (Swansea, Liverpool, Worcester and Boston USA papers, please copy) - Irish Examiner, 16 January 1932

William McCarthy is buried in Inch churchyard, Inch, County Cork, Ireland, the precise whereabouts unknown as the stones are very weathered.