Timothy John ¹ McCarthy was born in Boston, Massachusetts on 25 November 1857.

He was the son of Irish immigrants, Jeremiah McCarthy (b. 1827), a labourer, and Hannah Murray (b. 1831). His parents had emigrated around 1850 and 1854 respectively and had married about 1856. Timothy's known siblings were Dennis (b. 1859), Hannah (1865-1909), John (1867-1908), Jeremiah Fred (b. 1870), Charles (b. 1874) and William (b. 1878).

Timothy grew up in Boston and first appears on the 1865 and 1870 censuses living with his family at an unspecified address; by the time of the 1880 census was still living with his family and described as a dry goods clerk, his address then being given as 78 Hudson Street.

He was married to Mary Anastasia Haggerty (b. July 1860), also a first generation Irish American, on 26 June 1888; he was then described as a clerk. He and his wife would have six children: Anna Gertrude (b. 18 January 1890), Mildred Denney (b. 24 November 1891-1968), John Joseph (b. 4 November 1892), Justin Leon (b. 6 February 1895), Edmund Charles (b. 13 March 1897) and Brendon Murray (b. 17 May 1901). Their son John died two days short of his second birthday on 2 November 1894.

The family are shown on the 1900 census living at 69 Nelson Street, Dorchester and Timothy is described as a stationery buyer; by 1910 their home address is 52 Nelson Street and Timothy is still described as a stationery buyer in a department store. By 1912 he was a resident of 52 Nelson Street and worked as a buyer for the Boston department store Jordan Marsh.

Following a business trip in Europe, McCarthy and his friend and Jordan Marsh colleague Herbert Henry Hilliard boarded the Titanic at Southampton on 10 April 1912 as first class passengers. They held ticket number 17463 (which cost £51, 17s, 3d) and shared cabin E-46. McCarthy was no stranger to sea travel and had made at least twenty transatlantic voyages in his lifetime.

Timothy McCarthy died in the disaster and his body was later recovered by the Mackay Bennett:

The body was delivered to J. V. Finn of Boston on 30 April 1912 and was buried at Mount Calvary Cemetery, Dorchester, Massachusetts. His funeral, conducted from St Matthew's Church, Dorchester, attracted a large turnout of several hundred, including many from his workplace. Strangely, and not common for many Titanic victims, the State of Massachusetts issued a death certificate for him on 3 May 1912.

His headstone reads:

TIMOTHY J. M^CCARTHY
PERISHED ON S.S. TITANIC
APRIL 15, 1912, AGE 54 YRS
MARY A. HIS WIFE
MARCH 15, 1947 AGE 85 YRS
MILDRED D. DAUGHTER
OCTOBER 16, 1968, AGE 77 YRS
BRENDON M. SON
REST IN PEACE

His widow Mary continued to reside in Boston, never remarried and lived with her two daughters who remained spinsters. She died on 15 March 1947. Her daughter Anna worked as a bookkeeper and Mildred as a cashier; Mildred died on 16 October 1968 but what became of Anna is not clear.

His son Edmund also worked as a department store buyer; he was married to Julia Wholey (b. 1897) and had two children. He died in Wilmette, Illinois on 10 June 1949.

His son Justin later worked as a salesman and was married and raised a family. He died in Dedham, Massachusetts in 1960.

His son Brendon later worked as a window dresser in a department store; he retired to Brevard, Florida and died there on 8 December 1982.