I am a student on F1 visa studying in Ohio. I am scheduled to get 25000$ wire transferred from a foreign country. Will this amount be taxable when it lands in USA?

No, it is not taxable in the U.S. if it is gift, loan or your own money.

What MukatA says is true, but the wiring of that amount of money WILL require that you fill out some paperwork at the bank to properly identify the source of the money.

How would you prove that it is in fact a gift or loan?

By showing the original source of the money (to prove the gift), or by showing a promissary note (to prove the loan).