Where I work hired a private company to do all there cooking, in turn that company hired me, in this case can I date someone that works for who's employing my company?

I think it may be possible cause you don't work where she dose at least for the same company.

Well, yeah but I kind of messed up on my question. She is a senior at a high-school, that I graduated from the year b-4, I was then hired by a company hired by the school, so could we date?

Is she over 18? If so, then you can probably date. Check and see if your employee handbook mentions a situation like this. If it were me, I would just ask my boss and make sure. Like I said, as long as she is an adult (over 18), then it's probably OK, especially if you just graduated last year. But, like I said, check with your company to make sure you don't get in trouble.

I'm thinking that if you are working at the school, they are going to frown upon you dating a student. That's kind of tacky.
Play it cool and stay away from her when you're on school property.
Ask your employer and the school what they think about this.

Yeah, but I don't work for the school, the school hired a company, and I work for that company. And yes, I just graduated from this school, this girl graduates this year.

Well as long as you are not working there, I don't see where it would be a problem.

Well, I am at the school to work, but we would only be around each other away from the place, an she turns 18 soon then I don't think it would matter.

As long as you have no contact with her while you're there. The school might frown on a company who's employees are messing with the students.
If they get upset then you might get fired. So just stay away from her while you're working and on school property.

I think that is good advice. Ask your supervisor too if you can. I agree that they might not want an employee messing with students even if you are close to the same age. They might think it made the company look unprofessional.

All these views and no-on has any advice!!

Your question has been answered by several people. You need to ask your employer if that is going to be a problem, in the meantime don't go near your girl friend why you're at work.
What kind of advice were you looking for?
We can tell you it's OK or not OK, but you need to ask the people for whom it really counts, your employer.