There are many different insurance companies out there these days
. Some of them may be able to offer insurance without license in some areas. For people who have international drivers licenses, this can be very helpful.
The best way to do this is to tell them on the application that you do not have a drivers license. You can write zero into the box that says "years insured" and this should be enough to tell them you do not have not been licensed in a state you are in or possible in the United States at all.
Some places will not want to insure people who do not have a proper license, but they may be willing to anyway. If you could prove that you are qualified to drive a car but just haven't been registered with the Department of Motor Vehicles, then they may be willing to wave the requirement.
Driving without a drivers license is not recommended. Just because you have legal insurance does not mean that they will actually allow you to be driving. You should check the local laws in your area to make sure that you won't get in trouble for driving. There are a lot of places you might be able to go to do this. Checking the DMV website and looking for your state is probably the best bet.
If you have never had a drivers license anywhere, then you really shouldn't be driving. Even if you have known how to drive since you were very young, you could get into a lot of trouble for not having a license. For most people it is not hard to get licensed by the Department of Motor Vehicles.
Some people will have more trouble getting proper driving credentials. If they are citizens the reasons may include that they are not old enough or that they have had problems with driving in the past. People who have been charged with driving while under the influence of a drug or alcohol may not be able to get a license. People who have accumulated a lot of points on their licenses may not be able to get a new one issued either.
Getting insurance without license is possible, but it doesn't mean you are a legal driver. Sadly, not everyone is allowed to legally drive in the United States. There are a lot of laws you need to know before you hit the road.