McMullen, William (1888–1982), trade unionist and politician, was born in Lilliput Street, Belfast, son of Joseph McMullen, shop owner, of County Monaghan; his mother was a native of County Cavan. When he was two years old, his family moved to a bigger shop on Shore Road, Belfast, and his mother died when he was five. He received an elementary education at a local school and his first known involvement in trade union activities was when he helped Jim Larkin (qv) during the 1907 carters' strike in Belfast. While working in Harland and Wolff shipyard, he met James Connolly (qv) in 1910 and became Belfast chairman of Connolly's political party, the Independent Labour Party (Ireland). He went to Dublin in 1912 and spent some time there organizing the Dublin branch of the ILP. Mainly as a result of his radical activities, he was unable to find work in Belfast and emigrated to England and Scotland (1914–20). On his return to Ireland, he renewed his political involvement, but sharing Connolly's socialist republican analysis, he found himself politically closer to many catholics than protestants, notwithstanding his presbyterian background. He felt that he was withdrawn as the Labour candidate for Belfast East in the 1921 NI general election because Sinn Féin, which apparently provided financial assistance to help other Labour candidates in that election, refused financial assistance to McMullen claiming that he would take votes from Sinn Féin rather than from unionists. He was a senior figure in the Northern Ireland Labour Party when it was launched on 8 March 1924 and in the same year became the first protestant to be elected a poor law guardian for the predominantly catholic ward of Smithfield. He was then elected to Belfast corporation for the overwhelmingly catholic Falls ward in 1925 as a NILP candidate, despite the controversy he caused by dismissing a recent anti-socialist statement from the pope. He took the fourth and final seat for the Belfast West constituency in the general election to the NI parliament in April 1925, partly thanks to transfers from nationalist leader Joe Devlin (qv). He was fiercely critical of the boundary settlement of 1925 and delivered a one-hour attack on partition in the NI parliament. He lost the seat in the next NI general election (1929). His defeat was attributable to both the abolition of proportional representation and an explicitly confessional campaign by his nationalist opponent, Richard Byrne (qv), who was publicly supported by senior catholic clerics and the Irish News. Throughout his time in Belfast, he campaigned tirelessly for the rights of the poor, leading a torchlight procession of over 5,000 during the 1932 outdoor relief disturbances. He was later defeated in the NI parliamentary by-election for Belfast Central on 4 June 1934. On 28–9 September 1934, he emerged as chairman of the newly established but short-lived Republican Congress which consisted of Saor Éire members, IRA dissidents, and other republican socialists. He was secretary of the Belfast branch of the Irish Transport and General Workers' Union (1920–1937).
He moved to Dublin in 1937 where he lived for the rest of his life. He was appointed national organiser of the ITGWU in 1937, vice-president in 1939, and general president in 1946. In 1951 he wrote the introduction to Desmond Ryan's The Workers' Republic: a selection from the writings of James Connolly. He served in Seanad Éireann as part of the labour panel from 14 August 1951 until 16 September 1952, when, as a result of having refused on principle to pay a judgment debt, he was adjudicated to be a bankrupt, and under parliamentary law ceased to be a member of the oireachtas from that date. Then on 25 February 1953 he was deemed to have been elected to fill a casual vacancy in the senate, only to resign on 1 September 1953. In the same period he was one of five men appointed by the Minister for Industry and Commerce to serve on the board of the newly formed cross-border Great Northern Railway. He retired as a general president of the ITGWU in 1953, but during the course of that year he also presided over the Congress of Irish Unions, the forerunner of the Irish Congress of Trade Unions. He was appointed a director of CIÉ in the late 1950s and while in old age produced an official ITGWU typescript history of the 1907 dock strike.
His primary importance lies in his lengthy and successful trade union career, both as an activist in labour and social struggles, and as an organiser of Irish labour, particularly during the turbulent periods of labour history in the 1920s and 1930s. His impact was limited, however, partly because of the labour split over partition, but also because his protestant background made it easy for various nationalist and catholic opponents in Belfast to play the ‘religious card’ against him. He died suddenly in Dublin on 12 December 1982, and was survived by a son and daughters. His wife, Annie, had died some years earlier.