Ida Emily Leeson (11 February 1885 – 22 January 1964) was the Mitchell Librarian at the State Library of New South Wales from December 1932 – April 1946.

[1] "Leeson's interest in Australian and Pacific materials grew as she worked up the ranks at the Mitchell Library, eventually landing the senior position of principal accessions officer in 1919.

"[5] In this role Leeson was amongst the most senior staff at the library ranking behind William Ifould, Wright and Nita Kibble.

Zoe Emma Bertles was a strong contender to be Mitchell Librarian, but she lacked Leeson's wide knowledge of Australiana.

[15] With the development of microfilming technology, Leeson was to oversee the copying of thousands of records relating to the history of Australia that were held in archives and libraries around the world.

[17] During the sesqui-centenary celebrations in 1938 (150 years since the foundation of British settlement in Australia), Leeson was published in the Sydney Morning Herald describing the resources available in the collections at the Mitchell Library.

[18] Leeson's role as the Mitchell Librarian was referenced by poet James McAuley in his poem The true discovery of Australia.

[9] During the same time, she joined the movement of Theosophy in Castlecrag, where women advocated for their rights through creative works such as plays and literature.