Sue Donaldson (also known as Susan Cliffe) is a Canadian author and philosopher who is a research fellow in the Department of Philosophy at Queen's University, and an affiliate fellow in the department's Animals in Philosophy, Politics, Law & Ethics (APPLE) research cluster.
Her vegan cookbook Foods That Don't Bite Back was published in 2000, and her young adult novel Threads of Deceit was published in 2004. In 2011, Zoopolis: A Political Theory of Animal Rights, co-written by Donaldson and her husband Will Kymlicka, was published by Oxford University Press. In addition, she has coauthored a number of articles published in peer-reviewed academic journals, many on the topic of animal rights.
In Zoopolis and their other work on animal ethics, Donaldson and Kymlicka argue for a group-differentiated political conception of animal rights. Drawing upon citizenship theory, the pair argue that, though all animals should be protected by the same fundamental rights, individual animals should have different rights (and different responsibilities) depending on their group membership. Animals who form a part of mixed human/animal society (domestic animals) should be conceived of as citizens, while animals who are reliant upon the mixed society without being a part of it (liminal animals) should be conceived of as denizens. Wild animals, who live wholly or mostly separately from the mixed human/animal society, should be conceived of as sovereign over their own territory.