Brereton was born in Sydney, the fifth son of John Le Gay Brereton (1827–1886) and his wife Mary, née Tongue. His parents had travelled on the
Dover Castle from England, arriving in Melbourne on 25 July 1859 and then moved to Sydney. The younger Brereton was educated at
Sydney Grammar School from 1881 and the University of Sydney where he graduated
BA (1894), reading English under
Professor Sir Mungo MacCallum. He was editor of
Hermes, the student literary annual, and became the university's chief librarian in 1915. ==Career==