Baqubah ( ; BGN: Ba‘qūbah; also spelled Baquba and Baqouba) is the capital of Iraq's Diyala Governorate.

The city is located some 50 km to the northeast of Baghdad, on the Diyala River, just outside Iraq's so-called Sunni Triangle. In 2003 it had an estimated population of some 318,547 people.

The site has been inhabited continuously since pre-Islamic times as a center for agriculture and commerce. The name itself is thought to have come from the Assyrian language Baya 'quba, meaning "Yacoub's (Jacob) house." It served as a way station between Baghdad and Khorasan on the medieval Silk Road. It is now known as the center of Iraq's commercial orange groves.