The conceptions of jealousy used by philosophical writers are various, and, this paper suggests, largely inadequate. In particular, the difference between jealousy and envy has not yet been plausibly specified. This paper surveys some past analyses of this distinction and addresses problems with them, before proposing its own positive account of jealousy, developed from an idea of Leila Tov-Ruach(a.k.a. A. O. Rorty). Three conditions for being jealous are proposed and it is shown how each of them helps to tell the emotion apart from some distinct species of envy.It is acknowledged that the referents of the two terms are, to some extent, overlapping,but shown how this overlap is justified by the psychologies of the respective emotions.