During World War II, as many cities in northern Italy, Rezzato suffered extensive damage, leading to post-war rebuilding that significantly shaped its modern appearance.

For this reason, Rezzato was chosen by the Commonwealth War Graves Commission as the place to produce some headstones for its military cemeteries.

The origin of this town's name is thought to be the medieval "Regadium", which meant "royal court", a term used to designate the area surrounding the city of Brescia.

Benedictine monks contributed to the founding of Rezzato by draining the land and digging irrigation canals on the Valverde plain.

Rezzato became a free comune on 12 March 1299, when the inhabitants obtained by the bishop of Brescia Berardo Maggi the permission to autonomize the village from the Benedictine monastery of St. Eufemia.

In the 14th century, battles between Guelph and Ghibelline city-states led to domination over Milan and the nearby territory by the powerful Visconti family, backed by the emperor Henry VII.

The noble Giacomo Chizzola, after his withdrawal from politics, founded in his villa a school for the children of the rich families in Brescia, so that they could learn Latin.

Rezzato is located in the northern section of the Po Valley, immediately east of Brescia, at the foot of the Brescian Prealps.

The hilly system consists of the mountains Regogna, Fieno (the highest point of the town's territory at 430 metres (1,410 ft)) and Marguzzo, and two hills called Peladolo and Poggio San Martino.

The "medolo", which rises on the west side of Monte Regogna, has a much newer formation (178 million years ago) and is a stone made up of limestone marbles.

From Botticino descends the torrent Rino Musia that crosses part of the northeast wooded area of the town and then enters the city of Brescia.

Since the end of World War II, like other places in Lombardy, Rezzato has been host to two waves of mass migration: the first, workers from within Italy; the second, immigrants from outside the peninsula.

The first migration coincided with the economic miracle of the 1950s and 1960s, a period of extraordinary growth based on classic industry and public works.

The offices of the comune are housed in a building usually called the municipio or palazzo comunale, which in this case is seated in the central Piazza Vantini.

The shrine was built in a large wooded area in the northern part of the town (the so-called "Valverde", which means "green valley").

The site is one of the most important in the entire province because of the so-called "miracle of Valverde", a simultaneous apparition of the Virgin Mary and Christ which allegedly took place in the summer of 1399.

By throwing only one piece (symbolising plague) into the pond, the Virgin Mary interceded to save the village from war and famine.

According to the chronicles, another apparition occurred on 11 October 1711, when two boys who were picking chestnuts in the nearby wood suddenly saw a great light coming from the pond and a female voice calling them.

Built by the Benedictine monks in 1008 on the ruins of a Roman villa at the top of the St. Peter's Hill, it served as the main parish of Rezzato until 1460.

In the second half of 2017, due to the impossibility of an extension of the Brescia Metro to the town, the possibility of a reopening of the local train station is under consideration.