Ida Emily Leeson [1885-1964] attended Sydney Girls High and Sydney University, graduating with a BA in 1906 and finding a job as a library assistant. In 1909 she transferred to the Mitchell Library and by 1919 occupied one of the Library's senior positions, principal accessions officer. Over this period she developed a great interest in Australian and Pacific materials. In 1927, during a visit to Britain, she discovered, in the Public Record Office, the missing third volume of Matthew Flinders’ 1801-08 log.
In 1932 Ida Leeson became the first woman to be appointed Mitchell Librarian, but only after a public controversy about whether it was appropriate to appoint a female to such a senior position. The trustees reorganised the library's senior management, reducing the status and salary of the Librarian - a move criticised in vain by feminists such as Jessie Street.
Under Ida Leeson's direction the Mitchell Library consolidated its position as the pre-eminent repository of Australian and Pacific documents. Numerous important collections were acquired and the library's role expanded. During World War 2, while regular library services were curtailed, the establishment of General MacArthur's headquarters in Melbourne in 1942 led to frequent requests of the library for intelligence information about the Pacific. Ida Leeson was the right person to go to.
In April 1944 Alf Conlon secured her secondment as a research officer in ASOPA’s predecessor, the Directorate of Research and Civil Affairs. As Major Leeson she became a key member of Conlon's team which included people like John Kerr, James McAuley and JK Murray. Later she referred to Conlon as a “life-changer”. She did not return to the Mitchell after the war, preferring instead to become the first ASOPA librarian. In 1949 she moved to the South Pacific Commission where she worked until 1956.
Ida Leeson was a diminutive and forceful person who resisted easy classification. She became a trailblazer for women and for librarians and was a champion of the lively literary culture of Australia in the 1930s and 1940s. She was a close friend of Walter Burley Griffin and for some time Ida and her partner Florence Birch lived as part of the Griffins’ bohemian enclave in Castlecrag.
In her later years Ida Leeson continued to research for universities and other bodies and was generous with advice and assistance. She died on 22 January 1964.
Sources:  Baiba Berzins, ‘Australian Dictionary of Biography’, vol 10, Melbourne University Press, 1986.  Sylvia Martin, ‘Ida Leeson: A Life’, Allen and Unwin, 2006