Public law is the area of the law governing the relationship between individuals (citizens, companies) and the state. Constitutional law, administrative law and criminal law are thus all sub-divisions of public law.

In Canada, Public Law is referred to as "British Common Law", or just Common Law. When most people think of Common Law, they associate it with Common Law marriages where a man and woman who cohabit for an extended period of time and are considered in some jurisdictions as married.