Helen Ennis is an eminent photography curator, historian and writer.

She joined the Department of Photography at the National Gallery of Australia in Canberra in 1981 and was Curator of International and Australian Photography from 1985-92. She has extensive experience as an independent curator and writer specializing in the area of Australian photographic practice and biography. She lectured in Art Theory at the Australian National University School of Art & Design from 1996 to 2018 and became a Professor in 2014. She was Director of the Centre of Art History and Art Theory and the Sir William Dobell Chair of Art History at from 2014-18.

Major curatorial projects since 2000 include Mirror with a memory: Photographic portraiture in Australia (National Portrait Gallery, 2000); a retrospective exhibition of Olive Cotton's photographs (Art Gallery of NSW, 2000); In a New Light: Australian Photography 1850s-2000 (National Library of Australia, 2003 and 2004); a survey exhibition of the photography of European émigré Margaret Michaelis (National Gallery of Australia, 2005) Reveries: Photography and Mortality (NPG, 2007); A Modern Vision: Charles Bayliss, Photographer, 1850-1897 (NLA, 2008) and Things: Photographing the constructed world (NLA, 2012).

Helen Ennis writes extensively and her books include Intersections: Photography, history and the National Library of Australia (2004); Reveries: Photography and Mortality and Photography and Australia, both 2007; and Wolfgang Sievers, 2011. Margaret Michaelis: love, loss and photography (2005) was awarded the Victorian Premier's Non-fiction prize in 2006 and her most recent book Olive Cotton: A life in photography (Fourth Estate, 2019) was awarded the 2020 Magarey Medal for Biography and the Queensland Literary Awards Non-fiction prize.

Helen is a certified valuer for the Australian Government's Cultural Gifts Program.