As a proper noun:
* In English: "eye-oh" (like the word "eye" followed by "oh")
As a word in other languages:
* Italian: "ee-oh" (like the word "ee" followed by "oh")
* Latin: "ee-oh" (like the word "ee" followed by "oh")
As a musical note:
* In solfeggio: "ee-oh" (like the word "ee" followed by "oh")
It is important to note that the pronunciation of "Io" may vary depending on the region or dialect.