Papers, correspondence and press cuttings relating to Ireland, 1926-1978; Plaid Cymru, 1929-1965; Welsh political, economic and social affairs, 1931-1962; Pantybeiliau Folk School, 1933-1938; world economics, socialism and communism, 1934-1951; and Brittany, 1946; and personal papers, including correspondence, 1924-1978, diaries, 1921-1979, and academic papers, 1922-1946.

Correspondence and papers relating mainly to Lord Hooson's political career, including papers regarding parliamentary questions, 1967-1978; the Welsh Liberal Party, 1963-1979; Montgomery County Liberal Association 1965-1979; Welsh Affairs, 1961-1978; University College of Wales, Aberystwyth, 1961-1968; Dyfed-Powys Constabulary, 1970-1976; foot and mouth disease in Wales, 1967-1968; transport problems in Mid-Wales, 1962-1974; National Theatre for Wales, 1968-1969; Rural Development Board for Wales, 1967-1970; Mid-Wales Hospital Service, 1972-1973; Farmers Union of Wales, 1966-1973; Aberfan Disaster, 1966-1967; television and radio reception in Wales, 1969-1976; Wales Tourist Board, 1968-1976; Plaid Cymru, Welsh nationalism, Welsh language, Devolution, Federalism, Welsh economy, unemployment, Rhondda West by-election, etc., 1960s-1970s; the Liberal Party correspondence, 1960s-1970s, Liberal Party organisation and policies, 1967-1971; Liberals and the Industrial Relations Bill, 1971-1973; Lib-Lab pact, 1977-1978; Liberal Foreign Affairs Panel, 1966-1967; NATO and the North Atlantic Assembly, 1966-1978; correspondence files of the Welsh Liberal Party, 1966-79; engagement diaries, 1966-1978; typescript speeches and notes for speeches, 1960s-1970s; parliamentary accounts, 1970-1972; miscellaneous speeches, press statements, newspaper cuttings, etc., 1960s-1970s; political papers [c. 1950]-1973, produced by various parties; Local Government Reform in Wales, 1993-1994; the Liberal Party's Pantyfedwen Conferences, 1956-1963; the London Welsh School, 1983-1993, the Llangollen International Eisteddfod, 1986-1997; the provision of speech therapy and physiotherapy in Clwyd, 1984-1990; constituency correspondence and papers, [1960]-1979; personal correspondence, 1965-1979; and correspondence, press releases and newspaper cuttings relating to Jeremy Thorpe, former leader of the Liberal Party, 1967-1979; together with papers relating to his business interests including, Laura Ashley Holdings Plc., 1984-1997; Severn River Crossing Plc, 1990-1997; and his legal career, 1949-1962. A further collection of Lord Hooson's papers were received in May 2011 - this group remains uncatalogued.

Papurau, [c.1890au]-1995, a gasglwyd gan Dafydd Orwig, yn ymwneud yn bennaf â Phlaid Cymru, yn cynnwys deunydd yn ymwneud â chenedligrwydd, diwylliant, gwleidyddiaeth ac economeg Cymru, yn eu plith amrywiaeth o adroddiadau, datganiadau a chyhoeddiadau Plaid Cymru, 1958-1995, a hefyd peth ddeunydd yn ymwneud â'r Alban ac Iwerddon. = Papers,[c.1890s]-1995, collected by Dafydd Orwig, relating mainly to Plaid Cymru, and comprising material relating to nationality, culture, politics and economics in Wales, including a variety of Plaid Cymru reports, manifestos and publications, 1958-1995, and also some material relating to Scotland and Ireland.