Iocaste (eye'-o-kas'-tee, Greek Ιοκάστη) is a natural satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S. Sheppard, et al. in 2000, and given the temporary designation S/2000 J 3. Iocaste is about 5.2 kilometers in diameter, and orbits Jupiter at an average of 21,269,000 kilometers. It is also designated as Jupiter XXIV.

It is named after Jocasta, the mother/wife of Oedipus in Greek mythology.

Iocaste belongs to the Ananke group, retrograde irregular moons which orbit Jupiter between 19.3 and 22.7 Gm, at inclinations of roughly 150°.