Torre del Galgario, Medieval defensive tower in Bergamo, Italy.

Torre del Galgario is a cylindrical defensive structure in Bergamo with walls that taper toward the top and are built from sandstone throughout. Small openings punctuate the tower's height, and it stands as part of the city's medieval fortification network.

The Muraine were first raised in the 12th century to protect the Fossatum Comunis Pergami, the canal carrying water from the Serio that powered mills, workshops and dye works; the earliest defences were wooden. Bergamo's lower town was enclosed by 31 square towers and two round ones, of which the Galgario is one, plus six fortified gates, with walls about 6 m high. The Venetians rebuilt the walls between 1430 and 1438, and architects Antonio Agliardi and Pietro Isabello worked on them in 1521.

The name Galgario comes from calchera or calcarium, a lime kiln that once stood here. The tower gives onto a junction of five streets, and on the same largo stands the Chiesa del Galgario with its former monastery, later turned into the Caserma Nullo; the painter Giuseppe Ghislandi took his nickname Fra Galgario from it.

The tower is located at a road intersection in lower Bergamo near Via Frizzoni and the Montelungo military barracks. Visit during daylight hours to get the best views of its sandstone details and overall form.

The tower's name comes from calchera or calcarium, a lime kiln, not from any military term. In 1886 the mayor opened Bergamo's public baths in the Roggia Serio Grande starting from the tower, and from 1906 to 1920 a winter swimming race, the Cimento invernale, set off here along the canal toward Porta Sant'Antonio.