It was the the prophet Isaiah 700 years before Christ, the first to mention the earth was round.
Next time you hear it was during the Middle Ages that Gallileo or Newton came up with this concept, turn to Isaiah 40:22
22 He sits enthroned above the circle of the earth,
and its people are like grasshoppers.
He stretches out the heavens like a canopy,
and spreads them out like a tent to live in.
See, revelation paves the way to scientific achievements, as always.