Dame Gillian Mary Millicent Wagner (née Graham; born 25 October 1927) is a British writer, philanthropist and social administrator, and formerly chair of the children’s charity Barnardo’s,[1] the Thomas Coram Foundation and the Carnegie Trust.

She has published biographical and historical works, as well as reports on social care.

She was educated at Cheltenham Ladies' College and the University of Geneva, and later did a diploma in social administration at the London School of Economics, and subsequently a Ph.D., Dr Barnardo and the Charity Organisation Society: A reassessment of the Arbitration Case of 1877.

[5] Her 1979 biography of Dr Barnardo was the ‘first frank account of [his] character and career,[6] and Thomas Coram, Gent.

has been described as ‘a much-needed biography of this early pioneer of children’s charity.’[7] The exception to this is her most recent book, Miss Palmer’s Diary, a biography of her ancestor Ellen Palmer.