Islamic Republic is the name given to forms of government of several states. These states have Islam as a state religion and are governed by the principles of the Islamic law called Sharia. Some of these countries have both Sharia and civil law. Laws made by the state cannot contradict Sharia in some of these countries, and in other countries civil law is more dominant than Sharia law.
The following states call themselves Islamic Republic (non-exhaustive list)
Despite the similar name the countries differ greatly in their governments and laws. Of the Islamic republics, only Iran is a theocracy.