The Roman forum of Philippopolis (Bulgarian: Римски форум на Пловдив, Rimski forum na Plovdiv) is a rectangular forum (plaza) surrounded by the ruins of several ancient administrative buildings at the center of the ancient city of Philippopolis (modern Plovdiv). It was the center of public, administrative, commercial and religious life in the ancient city. Meetings, discussions, celebrations and state events were held there.

The forum covers an area of 20 hectares (49 acres), with 11 hectares (27 acres) excavated, which makes it the largest Roman forum in Bulgaria. The ancient city center was built in the 1st century AD during the reign of the emperor Vespasian, when ancient Philippopolis was laid out with a new urban plan and a forum according to the Roman model. The main streets of the city (the cardo and the decumanus maximus) intersect outside the eastern entrance of the forum. A complex of public buildings was built to the north, including the odeon, the library, and the treasury building.

The forum of the ancient city and its main street (cardo) are located at the very heart of modern Plovdiv's city center and main pedestrian area.