The Boulevard Périphérique (French pronunciation: [bulvaʁ peʁifeʁik]), often called the Périph, is a limited-access dual-carriageway ring road in Paris, France.

In 1846, the French War Ministry completed the defensive Thiers wall around Paris, including fortifications, a dry moat, a Rue Militaire and a large berm.

In 1859, the military engineering department gave conditional control of the perimeter to the precursor of the current Paris city council.

In the 1920s, the complete dismantling of the Thiers wall allowed further construction of what is today a series of over 20 connected boulevards encircling the city.

The Boulevards of the Marshals were almost fully completed by 1932, though the final three sections would not be added until 2005, closing the ring over 80 years after construction began.

Construction of the Périphérique began in 1958 on the remaining area once occupied by the Thiers Wall; the space not already taken up by the Boulevards of the Marshals measured anywhere from a few meters to the width of a city block.

In order to alleviate traffic congestion, the Périphérique was built more like a motorway than a wide boulevard, and was completed on 25 April 1973 under the presidency of Georges Pompidou.

The Périphérique became a victim of its own success, plagued by widespread congestion and blocked from expansion by dense surrounding urban areas.

Variable-message signs provide information on the estimated journey time to the next major exit, automatically generating updates every minute via a computer system using data from the sensors.