Lennon, James Gerard (‘Gerry’) (1909–76), solicitor and politician, was born in Armagh, eldest child among three sons and two daughters of James Lennon of the Desart, Armagh, town clerk of Armagh, and Margaret Lennon (née Stablien), a native of Germany. He began his education at St Patrick's Primary and St Patrick's College, Armagh, before attending QUB, and qualified as a solicitor, establishing his own practice in Armagh. His professional work was varied, but Lennon built up a reputation for his work in various cases involving the smuggling of cattle in the immediate postwar period. Later his interest as a keen angler was matched with frequent appearances for the Northern Ireland fisheries conservancy board in court.
His political career began at the Northern Ireland general election of November 1933, when he stood as an independent nationalist in Armagh South against the official nationalist candidate, Bernard O'Neill of the National League of the North, and P. J. MacLogan, a republican nominee. Lennon's decision to contest the seat followed a divisive nationalist selection convention at which a number of delegates withdrew after O'Neill had been selected. The basis of their discontent lay in the fact that, although it was accepted that the candidate would seek to represent all nationalist opinion in Co. Armagh, delegates from the northern half of the county, like Lennon, were excluded from voting in the selection process. After withdrawing, a number of dissenting delegates assembled on the roadside and proposed Lennon as a candidate. The contest that followed was a perfect example of the fragmentation of northern nationalism in the years after partition, with two nationalists pledged to taking their seats at Stormont, struggling against an abstentionist candidate. In the end MacLogan emerged as a comfortable winner with Lennon in second and O'Neill in third place.
After the death of Northern Ireland senator T. S. McLaughlin (1944) Lennon was nominated in June by nationalist MPs at Stormont to fill the vacancy. In this position (1944–72) he was to become heavily involved in the renewed effort to unite nationalist opinion within the north of Ireland, which led to the establishment (November 1945) of the Irish Anti-Partition League (IAPL). Lennon became an active member of the IAPL and served in various positions on its national executive. In its efforts to arouse fresh interest in the issue of partition in Ireland, Britain, and the USA, he travelled extensively to speak at public meetings. Little progress was made, however, and as the IAPL went into decline in the early 1950s, nationalist MPs and senators returned to conducting their affairs at Stormont without any formal party organisation or structure, and Lennon acted as the party's unofficial leader in the senate.
Outside politics he was an active member of the Ancient Order of Hibernians (AOH) and in 1951 became its national vice-president (1951–75). It was this dual role as nationalist senator and senior member of the AOH that was to bring him to public prominence in the early 1960s. In 1962 Eddie McAteer (qv), nationalist MP for Foyle, sought to improve relations between nationalists and unionists. Although he was particularly keen to interest the Orange order in his proposals, he lacked any contacts within the organisation; but his attention was drawn to the fact that Lennon was on reasonably friendly terms with Senator George Clark (qv), unionist leader in the senate and grand master of the Orange order in Ireland. He suggested that if Lennon and Clark could agree to discuss the problems facing Northern Ireland, they might set an example that others would follow. In August 1962 Lennon made public his willingness to meet Clarke and by October there began a process that became popularly known as the ‘Orange and Green talks’. Almost inevitably the talks failed, as the sides could not agree on the issues for an agenda. Lennon pushed for addressing concerns over alleged instances of discrimination against the minority community; Clark made clear that these could only be raised if and when nationalists accepted Northern Ireland's constitutional position within the UK. Thus by March 1963 the process had come to an end.
Although this attempt had failed, the nationalist party did not entirely abandon its efforts to improve community relations, and in 1965 developments elsewhere prompted it to take a symbolic but significant step. Following the meeting in January between Capt. Terence O'Neill (qv) and Seán Lemass (qv), the nationalist party for the first time since partition accepted the role of official opposition at Stormont, and the party leader, Eddie McAteer, formally nominated Lennon (February 1965) as leader of the opposition in the senate (1965–9). Lennon continued to sit in the senate till it was prorogued after the introduction of direct rule (March 1972). Although this marked the end of his active involvement in politics, he remained a member of the AOH and in 1975, following the retirement of James Dillon (qv), he became its president (1975–6). After a period of illness he died in Craigavon Area Hospital on 23 February 1976. He married (1938) Mary C. McLaughlin, whose father was a post-office linesman; they had no children. His papers are in the PRONI (D/3166).