Siobhan O'Sullivan is an Australian political scientist and political theorist who is currently an associate professor in the School of Social Sciences, University of New South Wales. Her research has focused, among other things, on animal welfare policy and the welfare state. She is the author of Animals, Equality and Democracy (2011, Palgrave Macmillan) and a coauthor of Getting Welfare to Work (2015, Oxford University Press) and Buying and Selling the Poor (2022, Sydney University Press). She co-edited Contracting-out Welfare Services (2015, Wiley) and The Political Turn in Animal Ethics (2016, Rowman & Littlefield International). She is founding host of the regular animal studies podcast Knowing Animals.