The names of the planets in our solar system have a variety of origins, but they were not all named by a single person:

* Mercury, Venus, Mars, Jupiter, and Saturn were named after Roman gods and goddesses. These names were given to them by ancient civilizations, likely the Romans themselves.

* Uranus was discovered in 1781 by William Herschel. He originally wanted to name it "Georgium Sidus" after King George III, but the name "Uranus" - after the Greek god of the sky - eventually gained acceptance.

* Neptune was discovered in 1846. Urbain Le Verrier, who mathematically predicted its existence, wanted to name it "Le Verrier", but the name "Neptune" - after the Roman god of the sea - became widely accepted.

So, while there isn't one specific person who named all the planets, the names were given over time by different cultures and individuals.