You're likely asking about the farthest moon from the Sun. There isn't a single moon that's always the farthest from the Sun, because the orbits of planets and their moons are constantly changing.

However, Neptune's moon Nereid currently holds the record for having the largest average distance from the Sun. It's often the farthest moon from the Sun, but because of its eccentric orbit, it sometimes swings closer to the Sun than some of the other outer moons.

It's important to note that the distance between a moon and the Sun is not a fixed value but changes constantly due to the elliptical nature of orbits.