Campbell, John Patrick (‘Seán’) (1889–1950), trade unionist, was born 4 March 1889 in Dublin, the son of John Campbell, a labourer, and Isabella Campbell (née Darragh). The family lived at 27 New Bride Street. He was educated at CBS Synge Street and then served an apprenticeship as a printer at Dollards Printing House, Wellington Quay, Dublin. Inspired by men such as James Larkin (qv), James Connolly (qv), and William P. Partridge (qv), he became involved in the labour and nationalist movements at an early age. After serving an apprenticeship as a compositor he joined the Dublin Typographical Provident Society (DTPS) in 1910. In 1915 he acted as honorary secretary of the anti-conscription committee and the John Mitchel centenary celebration committee. Two years later he was appointed as one of the three honorary secretaries of the central branch of Sinn Féin and played a prominent part in the organisation of the Sinn Féin Convention. In 1919 he was a delegate to the Dublin Trades Council, and from 1921 to 1951 he served as a full-time union official, as general treasurer of the DTPS. During this long period he oversaw the reorganisation of the union and was instrumental in maintaining harmonious industrial relations within the newspaper industry.
In June 1927 Campbell stood unsuccessfully as a Labour Party candidate in the constituency of Dublin City South. He was elected to the national executive of the Irish Trades Union Congress (ITUC) in 1930 and was its official Irish Labour representative at the International Labour Conference in Geneva from 1932 to 1938. In 1933 he was elected president of the ITUC and the following year became treasurer (1934–45).
Following independence there was a group within the ITUC that argued for the removal of British unions from Ireland and for a congress that consisted solely of Irish unions. The issue came to a head in 1945, when supporters of a uniquely Irish congress, including Campbell, resigned from the executive of the ITUC and withdrew their unions from the organisation. On 25 April Campbell became a member of the executive of the newly formed Congress of Irish Unions, the establishment of which created a schism within the Irish trade union movement for the next fifteen years.
A member of the Joint Industrial Council, Campbell took part in the commission of inquiry into banking, currency, and credit (1934–8). Along with Alfred O'Rahilly (qv) and William O'Brien (qv) he signed the No. 1 minority report that argued for ‘an organ for the issue and control of developmental credit’ within the state. He was also a member of many wage tribunals before the establishment of the Labour Court, serving on the advisory wages tribunal during the Second World War and the commission on vocational organisation (1939–43). He and Louie Bennett (qv) signed the report of the latter commission, but in a reservation declared that financial organisations should exist solely for the purpose of service to the community. First elected to the seanad in 1938 as a nominee of the Irish Trade Union Congress on the Labour panel, Campbell was returned in 1943 on the nomination of the taoiseach Éamon de Valera (qv) owing to dissension within the ranks of the Labour movement. He remained a member of the seanad until his death in 1950.
Throughout his life Campbell took a keen interest in Irish industrial development and was for many years honorary organiser of Aonach na Nodlag, a member of council and president (1938–40) of the National Agricultural and Industrial Development Association, and a member of a special committee of the national executive of the ITUC (1943) to examine the position of affiliated trade unions operating in Northern Ireland. He was also chairman of the Dublin Rheumatism Clinic Association, president (1942–4) of CBS Synge Street Past Pupils Union, a member of the visiting committee of Mountjoy Jail, and a member of the management committee of the Meath Hospital and Co. Dublin Infirmary.
Campbell was married to Ellen Donnelly and lived at Lyndene, 108 Kimmage Road East, Terenure, Dublin; they had no children. After being dogged by ill health for some years, he died 27 February 1950 in a Dublin nursing home, leaving an estate valued at £6,297.