Gregory Alan Mackie OAM is a South Australian cultural advocate and entrepreneur who has worked to promote the arts and culture in Australia. He was an elected Councillor at the Adelaide City Council (2000-2003, May 2020 - June 2022). He was co-founder and was managing director of independent bookshop Imprints Booksellers (1984–2007), served on many public bodies, including Arts SA and Adelaide Writers' Week, and founded the Adelaide Festival of Ideas in 1999. As of June 2022 he is CEO of the History Trust of South Australia, after being appointed to the position in 2016.