Rosa Praed, née Murray-Prior, was born in Bromelton, on the Logan River in Queensland, Australia. She was educated at home by her mother and by her own reading. She began writing as a child. Her mother died in 1868 and, as the eldest daughter of the family, Rosa ran her father's house and served as hostess when he entertained. In 1872, she married Arthur Campbell Praed, the scion of a well-to-do English family who had come to Australia to make his fortune, with whom she had four children.
After the failure of her husband's cattle station, in 1876 the family moved to England, where Rosa established herself as a writer. In
1880, she published her first book, An Australian Heroine, under the name Mrs. Campbell Praed. It was well-received and prompted her to write in quick succession, Policy and Passion (1881), Nadine; the Study of a Woman (1882), Moloch; a Story of Sacrifice (1883), and Zero; a
Story of Monte Carlo (1884).
Rosa's success as a writer was her entrée to the society of other writers, playwrights, actors, artists, and politicians. She collaborated on three political novels with Justin McCarthy, an Irish politician and friend, as well as The Grey River (1889), a coffee-table sized book about the Thames.
In 1894–1895, Rosa traveled to Japan and returned to Australia for a visit. She then wrote the novel Madame Izàn: A Tourist Story (1899), which raised the then-daring subject of an interracial marriage between a Japanese man and an Irish woman.
In the 1890s, she became estranged from her husband and separated from him. A few years later, she began living with Nancy Harward, a psychic medium. Much of her later fiction, some of which was written with Nancy, reflects her belief in spiritualism, reincarnation, and the supernatural. In 1902, she published her autobiography, My Australian Girlhood. She has been described as the first Australian novelist to achieve an international reputation.