Margaret Jane Long (5 April 1878-18 October 1956) was an Australian Baptist missionary who founded the Aborigines Inland Mission of Australia.

[1] Retta became a member of Petersham Baptist Church before joining the New South Wales Christian Endeavour Union.

[2] AIM began working in Aboriginal communities on recently gazetted reserves and with government permission, built churches and houses.

[1] Leonard died on 28 December 1928 and Retta continued as sole director with support from son Arnold, driving the AIM van.

After a fund was created and a suitable premises was found, the Native Training College was opened in Port Stephens, where the first two students entered in 1938.

[1] The Retta Dixon Home was opened using a subsidy given to Darwin missionaries when they returned in 1946 after they were evacuated and asked to care for Aboriginal evacuees during World War 2.