Australian-British artist Deborah MacMillan is the custodian of the ballets of her late husband Kenneth MacMillan.

MacMillan was born in Boonah, Queensland. She was educated in Sydney and studied painting and sculpture at the National Art School. Since 1970 she has lived in London, where she married Kenneth. She has designed ballets for the stage and television and returned to painting full-time in 1984, with subsequent exhibitions in London and Glyndebourne. Her work is in private collections in the USA and the UK.

MacMillan was a member of the Royal Opera House Board 1993–96 and was Chairman of The Friends of Covent Garden in 1996. Between 1996 and 1998 she was a member of the Arts Council of England and chaired the dance panel. She is an Honorary member of both the Board of Trustees of American Ballet Theatre and the National Committee of Houston Ballet. Previous positions include as a member of the committee of the Linbury Prize for Stage Design.