John Stuart Mill is generally considered to be a utilitarian; indeed, he himself supposed that he was one. On one principle of division, there are sometimes said to be two kinds of utilitarian, hedonistic utilitarians and agathistic utilitarians. Both of these agree that what makes an act right is whether or not the consequences of performing it are good, or are supposed by the agent to be good, but the hedonistic utilitarian thinks that only pleasure is good, whereas the agathistic utilitarian thinks that other things ate good as well. Commentators frequently complain that john Stuart Mill regarded himself as a hedonistic utilitarian, whereas in fact he was an agathistic one.

On another principle of division, there are also two kinds of utilitarian, act utilitarians and rule utilitarians. An act utilitarian thinks that the rightness of an action depends upon the goodness of its consequences; a rule utilitarian thinks that the rightness of an act depends upon the consequence of the rule to which it conforms or fails to conform.