Who discovered the planet mars?

Humans have known of Mars since before recorded history. Even 3600 years ago, the Babylonians wrote about Mars' looping motion across the sky and its changing brightness.
Since Mars is visible with the naked eye, early humans looking up at the night sky would have discovered Mars. In a time when only the moon and the stars lit up the night sky, Mars, the Red Planet, was a familiar and yet suspicious omen, a symbol for war and aggression for thousands of years because of its red color and its strange looping pattern in the sky.

The first actually recorded I think is Galileo.