This is a bit of a tricky question, as it depends on what you mean by "farthest." Here's why:

* Pluto is no longer considered a planet: It was reclassified as a dwarf planet in 2006.

* Neptune is the farthest *classical* planet: It consistently orbits beyond Uranus.

* Orbital paths are elliptical: Planets don't orbit in perfect circles. Their paths are elliptical, meaning their distance from the sun varies throughout their orbit.

So, the answer depends on the specific point in time:

* At most times, Neptune is the farthest. This is because its average distance from the sun is greater than Uranus.

* At certain times, Pluto *can* be farther than Neptune. This is because Pluto's elliptical orbit can take it further out than Neptune at times.

In summary: There is no single "farthest" planet. The answer depends on the specific moment in time and whether we're considering *classical* planets or also including dwarf planets like Pluto.