If you have a job offer in the United States and an employer willing to help you acquire a temporary (nonimmigrant) U.S. employment visa in order to accept it, but you have a criminal record, it is likely you are inadmissible. That means you would be ineligible for a work visa (or any other visa or green card) with which to enter the United States. This holds true even if you don't have a formal conviction or even a formal arrest on your record.
The good news is, if your criminal record renders you inadmissible, depending on the crime, you might still be able to ask the U.S. government to overlook ("waive") the crime for the purpose of obtaining legal employment in the United States. The not-so-good news is that you'll almost certainly need to hire a good immigration lawyer, which will add to the cost of the process.
The list all of the crimes that can cause someone to become inadmissible for a visa is a long one, and we cannot simply summarize it here. Because of the strict U.S. immigration laws, even the most non-serious of illegal activity can trigger inadmissibility, such as admitting that you once experimented with marijuana.
You can find several helpful discussions about types of inadmissibility and learn more about the different categories of crimes in this article on crimes and immigrant inadmissibility.
If you suspect that you might be found inadmissible, or if a U.S. embassy, consulate, or other immigration official tells you that you are inadmissible, you might be able to ask for a nonimmigrant waiver of inadmissibility. This is called a 212(d)(3) nonimmigrant waiver.
However, some serious crimes cannot be waived. In that case you would not be eligible for the waiver or for a work visa.
Many factors determine whether or not a criminal record or history can be overcome, such as the nature of the crime, the number of incidences, and the amount of time the person was imprisoned. To start, crimes that cannot be overcome are:
(This is why any foreign national facing criminal proceedings would be wise to consult an immigration attorney early on, to perhaps negotiate for a conviction that doesn't become an absolute bar to immigration.)
The 212(d)(3) nonimmigrant waiver is discretionary, meaning that the decision of whether or not to recommend it in your case will depend on whether or not you have convinced the officer assigned to you that you are deserving of the waiver. There is no special form to file with the visa application.
After you submit your visa application, the consular officer will schedule an interview for you and ask questions about your criminal history and the circumstances surrounding the crime (among other questions). The officer will decide whether a waiver should be granted. The decision will be based on:
After making a decision, the consular officer will make a report to Department of Homeland Security (DHS). If the officer did not completely feel that you deserve a waiver and makes an unfavorable recommendation, your application for a U.S. work visa will in all likelihood be denied.
Lying (making a misrepresentation) on a visa application is a fraud against the U.S. government. That act in itself triggers inadmissibility and ineligibility for a visa. If your failure to disclose the crime is discovered, your visa application will definitely be denied.
And then if you attempt to file another visa application in the future, you will find that your troubles are compounded. You will have two violations to overcome instead of just the original crime.
It is not possible to predict the outcome of your immigration case without an analysis of your crime and the facts surrounding your individual situation. You would be well served by consulting with an experienced immigration lawyer to discuss your situation before filing your application.