He has written extensively on Victorian Aboriginal history including editing the journals of George Augustus Robinson. He worked with The Victorian Aboriginal Corporation for Languages and in 2002 published the Dictionary of Aboriginal Placenames of Victoria and several related regional placename publications. He was one of the organisers of the second Trends in Toponymy conference in Ballarat in 2007, and is researching a book on Aboriginal toponymy for the ANU E-Press series. Other important published research includes work on massacre sites in Western Victoria in the 1995 publication Scars in the landscape : a register of massacre sites in Western Victoria 1803–1859. The interaction between the Wurundjeri people and the early settlement of Melbourne was told in the 2004 book – A bend in the Yarra : a history of the Merri Creek Protectorate Station and Merri Creek Aboriginal School 1841–1851, which Clark co-authored with Toby Heydon. Clark has also written on the Aboriginal presence on the Ballarat goldfields in the 1850s noting that while there is no evidence for any direct involvement of Aboriginal people in the events of the Eureka Rebellion in 1854, aboriginal people may be relevant to the Eureka story through the event taking place on Wathaurong aboriginal land. The early policing of the Goldfield was done by the Native Police Corps, and oral history that Aboriginal people looked after some of the children of the Eureka miners after the military storming of the Eureka Stockade and subsequent massacre of miners.
Major works
Scars in the landscape : a register of massacre sites in Western Victoria 1803–1859, AIATSIS,
A bend in the Yarra : a history of the Merri Creek Protectorate Station and Merri Creek Aboriginal School 1841–1851 / Ian D. Clark and Toby Heydon. Aboriginal Studies Press, 2004.
The Port Phillip journals of George Augustus Robinson : 8 March – 7 April 1842 and 18 March – 29 April 1843 / edited and with an introduction by Ian D. Clark. Robinson, George Augustus, 1791–1866. Published Melbourne: Department of Geography, Monash University, 1988.
Dictionary of Aboriginal placenames of Victoria / Ian D. Clark, Toby Heydon. Published: Melbourne : Victorian Aboriginal Corporation for Languages, 2002.
The journals of George Augustus Robinson, chief protector, Port Phillip Aboriginal Protectorate / Ian D. Clark, editor 2nd edition Published: Melbourne, Vic. : Heritage Matters, 2000.
Aboriginal languages and clans : an historical atlas of western and central Victoria, 1800–1900, Published: Melbourne, Vic. : Dept. of Geography and Environmental Science, Monash University, c1990.
Place names and land tenure : windows into Aboriginal landscapes : essays in Victorian Aboriginal history / Ian D. Clark. Published: Ballarat, Vic., Ballarat Heritage Services, c2003.
Note: this is a list of major published writings, not a full list of research or publications.