Smith's primary research interests include ethics, moral psychology, philosophy of mind and action, political philosophy and philosophy of law. He is the author of The Moral Problem (Blackwell, 1994), for which he was awarded the American Philosophical Association Book Prize 1994-6; Ethics and the A Priori: Selected Essays on Moral Psychology and Meta-Ethics (CUP, 2004); and co-author of Mind, Morality and Explanation: Selected Collaborations (OUP, 2004), a collection of papers written in various combinations by Smith, Frank Jackson and Philip Pettit. He is also the editor of Meta-Ethics (Dartmouth, 1995), and the co-editor of Reason and Value: Themes from the Moral Philosophy of Joseph Raz (OUP, 2004) with Jay Wallace, Philip Pettit, and Samuel Scheffler; The Oxford Handbook of Contemporary Philosophy (OUP, 2005) with Frank Jackson; and Common Minds: Themes from the Philosophy of Philip Pettit (OUP, 2007) with Geoffrey Brennan, Robert Goodin, and Frank Jackson.
Smith has held visiting posts at universities in the USA (Ann Arbor, Arizona, Chapel Hill, Princeton), the UK (Bristol), Sweden (Uppsala), Germany (Bayreuth), Japan (joint between Kyoto, Osaka Dental, Kwansei Gakuin, Senshu, and Keio), and New Zealand (Canterbury, Otago, Victoria). He is Fellow of the Australian Academy of Humanities and the Academy of Social Sciences in Australia.