Clio was a muse. Her name means 'to celebrate', 'to praise', 'to acclaim'. She was the goddess of the arts. As a muse, she was known for heroism, poetry, and history. She has the title of 'The Proclaimer'. She is credited for introducing the Phoenician alphabet into Greece. An asteroid was named after her, discovered on August 25, 1865. Her mother was Hyacinth and fathered by Zeus. She married Perus, the king of Macedonia, part of modern Greece, Bulgaria, and Yugoslavia. Worshipped in Greece and Macedoina.
I really like this name. It’s original, pretty and unique, but no too out-there. Clio is great alternative to the overused Chloe. The only reason I wouldn’t use it as a legit name is because of the Renault Clio. Not that it’s a bad car, but I wouldn’t want people to think that I’d named my child after it. So, I would use Clio as a nickname for the gorgeous name Clíona.
There aren't to many feminine names ending in O that 'work' in English. And this is in my opinion is the most feminine sounding one of them. I prefer this spelling because I love the mythology connection to it, and it seems more of a stand alone name while Cleo always look more like a nickname for Cleopatra.