If my son interned in Chicago (college aged) , and lives in Ohio but made no money in Ohio, does he have to file an Ohio State and City return?

[Hal_Al]

Yes.

As you may conclude from the other answer, the Ohio filing requirement is wishy washy. The simple answer is he does not need to file a state return if his total income  was less than $10,850. Otherwise, he needs to file, even though the income was earned out of state.. Ohio will give him a credit, or partial credit, for any tax paid to Illinois.

If he is your dependent, he must file a city return for the city you live in. Even if he isn't your dependent, he must file a city return for the city of his permanent residence. There is no minimum income filing requirement for most Ohio cities, although some (most) exempt people under 18.

[Hal_Al]

Answer was edited

[KarenJ]

If his Ohio adjusted gross income (Ohio IT 1040, line 3) is less than or equal to 0 (zero) than he does not have to file a return.

Please see page 11 https://www.taxformfinder.org/ohio/income-tax-instructions

He may need to fill out an Exemption form for the city.  What city did he live in during the year?