Can the school hold on to my phone overnight without permission?

You may not like this answer but if you are a minor and your school has a rule or regulation about cell phones and you violate it, then the general rule is that they have the right to confiscate it. Depending on your school regulations they very likely have the right to retain it for a reasonable amount of time and would have to turn it over only to your guardian or parent, since a minor child, under legal age and not emancipated, does not legally own personal property in Ohio anyway. You may think of it as "your" phone, but it is legally not your property. So, yes, they have the right to keep it overnight. Your best bet is to apologize, say it was just a mistake and won't ever happen again, and next time leave it shut off in your locker at school or at home in the first place. Repeat or serious violations of school regulations or rules can result in suspension or expulsion. Enough of that on your school record and you could have to do over the school year. Knowing how bad most kids want to get out of school, the risk just isn't worth it. If this answer was helpful please give it a Vote UP review below. Thanks for asking and good luck.