who discovered that the earth was round

Nobody “discovered” the Earth was round in a single eureka moment; knowledge of a spherical Earth developed gradually in ancient Greece and was refined over centuries.

Quick Scoop

• Pythagoras (around 500 BCE) is often credited as one of the first to propose that the Earth is round, reasoning by analogy with the round Moon.

• Anaxagoras (5th century BCE) used the curved shape of Earth’s shadow on the Moon during lunar eclipses as evidence for a spherical Earth.

• Aristotle (4th century BCE) gave some of the earliest systematic arguments:
  • Earth’s circular shadow on the Moon in eclipses.
  • Different constellations become visible as you travel north–south, which fits a curved surface.

• Eratosthenes (3rd century BCE) did not discover the shape but famously measured Earth’s circumference with surprising accuracy using shadows in two cities and basic geometry.

• Much later, the Magellan–Elcano circumnavigation (1519–1522) offered practical, global-scale confirmation that you can sail around the planet.

So who “gets the credit”?

If the question is “who discovered that the Earth was round,” historians usually answer with the ancient Greeks , not Columbus or any single explorer.

• For an early idea : many name Pythagoras.
• For a clear argument : many highlight Aristotle.
• For a quantitative proof-style measurement : Eratosthenes is the star.

So, the most accurate short answer is:

The idea that the Earth is round goes back at least to Pythagoras and other ancient Greek thinkers and was solidly argued by Aristotle and measured by Eratosthenes, centuries before Columbus.

Information gathered from public forums or data available on the internet and portrayed here.