In this paper, I endorse the idea that age is a defensible criterion for eligibility to vote, where age is itself a proxy for having a broad set of cognitive and motivational capacities. Given the current (and defeasible) state of developmental research, I suggest that the age of 16 is a good proxy for such capacities. In defending this thesis, I consider alternative and narrower capacity conditions while drawing on insights from a parallel debate about capacities and age requirements in (...) the criminal law. I also argue that the expansive capacity condition I adopt satisfies a number of powerful and complementary rationales for voting eligibility, and conclude by addressing challenging arguments that, on the one hand, capacity should not underlie voting eligibility in the first place, and, on the other, that capacity should do so directly and not via any sort of proxy, including age. (shrink)