This paper presents a new analysis of the concept of non-instrumental need, and, using it, demonstrates how a need-satisfaction theory of well-being is much more plausible than might otherwise be supposed. Its thesis is that in at least some contexts of evaluation a central part of some persons’ well-being consists in their satisfying certain “personal needs”. Unlike common conceptions of other non-instrumental needs, which make those out to be moralised, universal, and minimal, personal needs are expansive and particular to particular persons, generated rather by persons’ non-moral personal commitments. Against objections to the contrary, I show how these are genuine necessities, since unlike mere desires and freely escapable aims, personal needs constitute objective, inescapable, and non-compensable practical requirements. The personal-need-satisfaction theory of well-being combines objectivity with subject-dependence in novel ways, and motivates well-being pluralism at the level of individual agency. Implicating necessity as it does in the structure of individual well-being, this account presents a robust challenge to ethical and political theories that rely on the intrapersonal aggregation of well-being to be unproblematic.