Flora Eldershaw (1897-1956) was an author and critic, born in Sydney. She grew up in the Riverina district. She studied at the University of Sydney where, in 1916 she met Marjorie Barnard, a fellow student. To the shy Barnard, Flora appeared a "dark-haired, vivacious girl, a fountain of energy, ideas and laughter".

Using the pseudonym "M. Barnard Eldershaw", Flora and Marjorie collaborated on their first novel, A House Is Built (1929), which shared first prize in the Bulletin novel competition with Katharine Susannah Prichard’s Coonardoo. They wrote Green Memory (1931), The Glasshouse (1936) and Plaque With Laurel (1937). Under her own name, Eldershaw published Contemporary Australian Women Writers (1931) and edited The Peaceful Army (1938).

A leading figure in Sydney literary circles, in 1935 Eldershaw had become the first woman President of the Fellowship of Australian Writers. In 1938 Eldershaw helped to persuade the Federal government to expand the Commonwealth Literary Fund to include grants (as well as pensions) for writers and funding for university lectures on Australian literature.

After delays due to wartime censorship and paper shortages, Eldershaw and Barnard's final novel, Tomorrow and Tomorrow [and Tomorrow] appeared in 1947 (the uncensored version in 1983). This book was widely considered to be the work of Barnard alone until recent scholarship established Eldershaw's contribution. Its political content was exploited by William Wentworth in 1952 to support his allegation that Eldershaw and other prominent members of the C.L.F. advisory board were communist sympathizers.