Who was the first to name our planet "Earth"?

Answer 1

This depends on what you mean by "Earth." The word earth comes from the Old English "eorthe" which was used before 950 AD. There are cognate words in Old Norse like "jorth" (pronounced something like "yoo-erth").

To answer your question directly, no one knows who first spread his or her arms wide and said, "Earth", but it was a long time ago.

HTH

Charles