An Islamic republic is a form of government, known as a theocracy, advocated by some Muslim religious leaders in the Middle East and Africa.

Under the rule of an Islamic republic the laws of the state are compatible to the laws of Islam, although the state remains a republic. For example, in the Islamic Republic of Iran, the sole leader is a high-ranking religious cleric, theoretically elected indirectly by people, while the president and the parliament members are elected by direct vote of the citizens (although many feel that Iranian elections are not democratic). Iran's Islamic republic is in contrast to the marginally democratic state of Pakistan, where Islamic laws are considered to override the state's laws.

The Islamic Republic of Iran (1979– ) is one of the first contemporary nations to formally atempt to follow this form of the government after a revolution. However, some people believe that since the death of the republic's founder Ayatollah Khomeini, Iran's religious infrastructure is crumbling, and the nation is slowly edging away from the original ideas of Khomeini or the people who revolted against the previous monarchy.

Today, the creation of Islamic republics is the rallying cry for many Muslim fundamentalists all over the world. Many of these Muslims advocate the abolishment of the monarchies of the Middle East, regimes which they believe to be overly secular or otherwise destructive to Islam.

The nations of Afghanistan, Iran, Mauritania, and Pakistan all have "Islamic republic" in their full name, though they differ greatly in individual governments and laws.