Who can see my payment history on PayPal?

You.

Unless you have given your login info to someone else, or someone has seen transaction notification emails on your screen while you have had your email open.

If in doubt, change you password - and make sure its a strong one, ten mixed characters (not words) with uppercase, lowercase, numbers and symbols.

I can, I can. Ha ha.

You. Your parents can, too, if they have access to the page.

You can