Where does “Callisto” come from?

Callisto comes from Ancient Greek Καλλιστώ, the superlative form of Ancient Greek κᾰ́λλος meaning "beauty."

Ancestry of “Callisto”, step by step

Step	Language	Word	Meaning
1	Latin	Callisto	—
2	Ancient Greek	Καλλιστώ	—
3	Ancient Greek	-ω	—
4	Proto-Indo-European	-éti	—

Callisto — Etymology, Origin & Word History | Etymology Explorer