ABSTRACT In his book, A Theory of Justice, John Rawls argues against the inclusion of non-human animals within the scope of the principles of justice developed therein. However, the reasons Rawls, and certain commentators, have advanced in support of this view do not adequately support it. Against Rawls' view that ‘we are not required to give strict justice’ to creatures lacking the capacity for a sense of justice, it is initially argued that (i) de facto inclusion should be accorded non-human animals since their exclusion strains just institutions, and (ii) Rawls' account of the sense of justice has implicit and undefended human chauvinist elements. Two further counter-arguments are then developed in more detail. First, the suggestion that some non-human animals do have a capacity for a sense of justice is explored. Second, the suggestion that the capacity for a sense of justice is unrealised in so many human beings that Rawls' basis for marking out a special place for them is undermined is explored. Attention is next given to Rawls' characterisation of the participants in the original position. It is claimed that there are no good reasons for disallowing the possibility that these individuals turn out to be non-human animals in the real world. If sound, this claim brings non-human animals directly within the scope of Rawlsian principles of justice. The claim is defended against three objections.