Of the planets in the solar system, Neptune is the farthest away from Earth. Depending on where each planet is in its orbit, Neptune is between 2.7 and 2.9 billion miles away from Earth.
Pluto used to be considered the farthest planet away from Earth at 4.67 billion miles away at its greatest distance. Pluto's place in the solar system never changed, but scientists' classification of Pluto did. In 2006, members of the International Astronomical Union voted to change the definition of the word "planet" in a way that excluded Pluto, making Neptune the most distant planet. Pluto is now considered a dwarf planet, and scientists estimate that there are hundreds of other dwarf planets like it in the solar system.