The Walls of Grosseto (Italian: mura di Grosseto), known also as Medicean Walls (Italian: mura medicee), are a series of defensive brick walls surrounding the city of Grosseto in southern Tuscany, Italy.

Walls of Grosseto
Mura di Grosseto
Grosseto, Tuscany, Italy
Porta Vecchia
Walls of Grosseto
Coordinates	42°45′43″N 11°07′03″E / 42.761806°N 11.1175°E / 42.761806; 11.1175
Type	Defensive walls
Site information
Owner	City of Grosseto
Controlled by	Grand Duchy of Tuscany (1565–1859)
Open to the public	yes
Condition	Well-preserved or intact
Site history
Built	1565–93
Built by	Cosimo I de' Medici, Grand Duke of Tuscany Architects involved: Baldassarre Lanci (1565–71) Marino Lanci (1571–74) Simone Genga (1574–82) Alessandro Pieroni (1587–93)
Materials	Brick

The fortifications were commissioned by Cosimo I de' Medici, after the conquest of the Republic of Siena and its annexation to the Grand Duchy of Tuscany. The walls were designed by engineer-architect Baldassarre Lanci in 1564. Construction began in 1565 and was completed in 1593.

During the 19th century, under the rule of Leopold II, the walkways of the walls were demilitarized and transformed into gardens and promenades.