Rosa Sibella Macarthur Onslow

Rosa Sibella Walton Macarthur-Onslow CBE (4 June 1871 – 16 July 1943) was an Australian charity and church worker. She inherited and managed Camden Park in New South Wales. Guests at the house included the Duke and Duchess of York.

Life Macarthur-Onslow was born in 1871 at Camden Park which was her family's 20,000 acre estate. Her parents were Elizabeth ( Macarthur) and Captain Arthur Alexander Walton Onslow, R.N. who became a member of parliament. While her brothers were sent to private schools in Australia and Britain for their education, she was taught by a German tutor and her mother. Her father died in 1882 and her mother took over the management of the estate. Macarthur-Onslow would organise frequent musical evenings at Camden Park which were led by Emmeline Woolley and Ethel Charlotte Pedley.

Her mother's father had helped to establish the Australian wool industry. Her mother was the end of her father's line. In 1892, a Royal license was obtained to allow her mother and her children to take the surname Macarthur-Onslow. Macarthur-Onslow was disappointed to find that Camden House had not been included. A reception in her honour attracted many VIPs including NSW Premier Thomas Bavin. In 1931, she decided to exchange houses with her brother James William MacArthur-Onslow. Camden House had only been given to her for her lifetime and she knew that her mother had been very keen to see the house remain in the family.

Macarthur-Onslow died in 1943 in the parish of Menangle.

Publications In 1914 she published "Some Early Records of the Macarthurs of Camden". This was a work that her mother has nearly finished and Sibella completed, edited, and published it.