I had trouble finding any information about this online but was curious if anyone here knew: once I finish my undergrad in the US, is it at all possible to begin my graduate at Cambridge in the UK (even if highly unlikely)?
Yes.
Yes, you would begin with a masters (typically 1 year) before a PhD (3 years), you don’t go straight into a 4-6 year PhD program like in the US.
You will need to be right at the top of your class (3.9+ GPA/summa cum laude would be advisable), with very strong recommendations, although prior research experience is not as common in the UK.
The challenge is finding funding, since that isn’t automatic for those admitted, and is why only about one third of those admitted actually attend. For a non-UK/EU student the costs are around $40K to $50K per year including living expenses for most courses. You can apply for internationally competitive scholarships (the Gates scholarship is the Cambridge equivalent of Oxford’s Rhodes scholarship) and some colleges also offer funding for specific subjects or nationalities based on the wishes of the donor. You may have to reapply for the PhD funding after the masters, and you will usually need to get a distinction in the masters course to continue to the PhD.
PhD funding is not based on the TA/RA model like in the US, you are not expected to work/teach for the money, though you have the option to supervise undergraduates (small groups of 2-3 at a time to go through problem sets or essays) and get paid for it. But the corollary is that you need to get on and finish in the three years that are funded.
Okay thanks a lot that really helps