Consequentialism is a major moral theory in contemporary philosophy: it is the view that the only thing that matters when making moral decisions is the outcome of those decisions. Consequentialists hold that to morally assess an act, we must first evaluate and rank the various ways that things could turn out depending on whether it or some alternative act is performed. Whether we should perform that act thus depends on how its outcome ranks relative to those of its alternatives. Consequentialism rivals deontology, contractualism, and virtue ethics, but, more importantly, it has influenced contemporary moral philosophy such that the consequentialist/non-consequentialist distinction is one of the most central in normative ethics. After all, every plausible moral theory must concede that the goodness of an act’s consequences is something that matters, even if it’s not the only thing that matters. Thus, all plausible moral theories will accept that both 1) an act’s producing good consequences constitutes a moral reason to perform it, and 2) the better its consequences, the more of a moral reason there is to perform it. In this way, much of consequentialist ethical theory is important for normative ethics in general. This Oxford Handbook contains thirty-two previously unpublished contributions by top moral philosophers examining the current state of play in consequentialism and pointing to new directions for future research. The volume is organized into four major sections: foundational issues; objections to consequentialism; its forms and limits; and consequentialism’s implications for policy, practice, and social reform.