If you dream that you are in jail, it can mean you are feeling restricted. Another person or an external circumstance could be causing this feeling of restriction, or you could be causing it yourself, especially if you, yourself are the jailer.
The dream could be telling you that your own fears and inhibitions are preventing your from moving on in life.
Dreaming that you are in jail can be a sign that you feel trapped in a difficult situation. If you dream of escaping from jail, you are looking for a way to get out of your predicament.
A dream that you are alone in a jail can mean that you are feeling isolated from others.
Dreaming that you are put in jail for no reason can mean that you believe you are being judged unfairly in real life.