Yes, you will need a Tier 4 Student Visa, which you can apply for after you have been offered a place on a UK University course. (Gov.uk, 2015) 1

You should allow around three months for your visa to be processed, so you should apply to your chosen Universities early, around 6 months in advance. You will need:

• Confirmation of Acceptance for Studies (CAS) with a licensed Tier 4 sponsor
• have enough money to support yourself and and pay for your course, in the region of £25,000, depending on your circumstances. (This money must either have been in your personal bank account in full for a minimum of 28 days before you apply for the visa, or you must have evidence of an approved US loan which is accepted by the UK university).2

• 1. Gov.uk (2015) "Tier 4 (General) student visa", https://www.gov.uk/tier-4-general-visa/overview
• 2. http://talk.uk-yankee.com/index.php?topic=85789.0