Upvote:8
The US shares criminal records with several other countries, including the UK. UK border officers will be able to access your US criminal history.
You should disclose the criminal conviction on your visa application. Doing so does not automatically mean you will be refused; that depends on the specific crime and how much time has passed since you served your sentence. (Though, based on the details you have provided, I would expect that not enough time has passed for you to be able to get past this hurdle.) However, if you do not disclose the conviction, the UK will consider this deception and you are likely to receive a 10 year ban from entering the UK.