Una Fielding was born in Wellington, New South Wales to Anglican clergyman and author Rev. Sydney Glanville Fielding and his wife Lucy Frances (née Johnson). The eldest of six children, Una attended a private school in Windsor before starting at St Catherine's School, Waverley in 1900. In 1907 she won a bursary to the University of Sydney; after graduating with a Bachelor of Arts (BA) in 1910 she spent six years teaching French and English.[1][2]