An Islamic republic is a state under a particular theocratic form of government advocated by some Muslim religious leaders in the Middle East and Africa. In an Islamic republic the laws of the state are theoretically required to be compatible with the laws of Islam, while the state remains a republic.

In the Islamic Republic of Iran (established in 1979) the sole leader is a high-ranking religious cleric, theoretically elected indirectly by people, while the president and members of the legislature are elected by direct vote of the citizens (although many feel that nonetheless Iranian elections are not truly democratic). Iran's Islamic republic is in contrast to the partially democratic state of the Islamic Republic of Pakistan (founded in 1956) where Islamic laws are nonetheless considered to override laws of the state.

Iran is one of the first contemporary nations to formally attempt 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.