What jobs can an undergraduate degree in theoretical physics get you?

Honestly, an undergraduate degree in physics won't allow you too many options.

It's not like engineering. An undergraduate degree in engineering will open up many job opportunities for you. Eventually, you could end up in a high-paying supervisory position.

Unfortunately, not so in physics. The really good jobs all go to the PhD physics people. And that's because a country needs many engineers, but only a few physicists. Think of the engineers as the builders and the physicists as the masterminds at the very top.

So if you have (or want) a physics undergraduate degree, you really have four choices.

1. Get a job as an assistant in a program run by a PhD. You'd be doing boring, repetitive work most of the time.

2. Go on for your PhD in physics. But know that only those with the best grades and best research work will eventually get a good job.

3. Switch to engineering.

4. Become a high school physics teacher. There is a shortage of high school physics teachers, and all you need is an undergraduate degree.  If you can get a position in a good school, teaching physics can be a great career!

EDIT: By the way, everything that I said about physics is also true about chemistry.