O'Connor entered journalism as a junior reporter on Saunders' Newsletter, a Dublin journal, in 1867. In 1870, he moved to London, and was appointed a sub-editor on The Daily Telegraph, principally on account of the utility of his mastery of French and German in reportage of the Franco-Prussian War. He later became London correspondent for The New York Herald. He compiled the society magazine Mainly About People from 1898 to 1911. O'Connor was elected Member of Parliament for Galway Borough in the 1880 general election, as a representative of the Home Rule League. At the next general election in 1885, he was returned both for Galway and for the Liverpool Scotland constituencies, which had a large Irish population. He chose to sit for Liverpool, and represented that constituency in the House of Commons from 1885 until his death in 1929. This was the only constituency outside the island of Ireland ever to return an Irish Nationalist Party MP. O'Connor continued to be re-elected in Liverpool under this label unopposed in the 1918, 1922, 1923, 1924 and 1929 general elections. , London. The inscription reads, "His pen could lay bare the bones of a book or the soul of a statesman in a few vivid lines." From 1905 he belonged to the central leadership of the United Irish League. During much of his time in parliament, he wrote a nightly sketch of proceedings there for the Pall Mall Gazette. He became "Father of the House of Commons", with unbroken service of 49 years 215 days. The Irish Nationalist Party ceased to exist effectively after the Sinn Féin landslide of 1918, and thereafter O'Connor effectively sat as an independent. On 13 April 1920, O'Connor warned the House of Commons that the death on hunger strike of Thomas Ashe would galvanise opinion in Ireland and unite all Irishmen in opposition to British rule. O'Connor founded and was the first editor of several newspapers and journals: The Star, the Weekly Sun, The Sun, M.A.P. and T.P.'s Weekly. In August 1906 and as Father of the House, O'Connor was instrumental in the passing by Parliament of The Copyright Law for Music Act 1906, known as the T.P. O'Connor Bill, following many of the popular music writers at the time dying in poverty due to extensive piracy by gangs during the piracy crisis of sheet music in the early 20th century. The gangs would often buy a copy of the music at full price, copy it, and resell it, often at half the price of the original. The film I'll Be Your Sweetheart, commissioned by the British Ministry of Information, is based on the events of the day. He was appointed as the second President of the Board of Film Censors in 1916 and appeared in front of the Cinema Commission of Inquiry, set up by the National Council of Public Morals where he outlined the BBFC's position on protecting public morals by listing forty-three infractions, from the BBFC 1913-1915 reports, on why scenes in a film may be cut. He was appointed to the Privy Council by the first Labour government in 1924. He was also a Fellow of the Chartered Institute of Journalists, the world's oldest journalists' organisation. It continues to honour him by having a T.P. O'Connor charity fund.
Publications
O'Connor wrote a number of books, including Lord Beaconsfield – A Biography ; The Parnell Movement ; Gladstone's House of Commons; Napoleon; The Phantom Millions; and Memoirs of an Old Parliamentarian.
