The etymology of the name is unknown: Grandate may derive from granum-datum, land which produces wheat, or from grandinatum in accordance with an old tradition which says that the country surrounding Como is notorious for its sudden storms. Little is known about old settlements in the area of Grandate. The discovery of many archaeological relics in the neighbouring villages (Camerlata, Rebbio, Lucino, Albate, Prestino, Prato Pagano) and, above all, Grandate's closeness to the necropolis of Cà Morta may suggest that the area was already inhabited in prehistoric times. Some historians believe that Grandate was founded by the Romans. It is known for sure that in the Middle Ages, the Roman route Via Regina that leaded from Milan to Como crossed Grandate at today's San Poso. Some houses were built there in order to put up pilgrims on their way. In the 8th or 9th century, a little chapel dedicated to St. Adalbert with a little graveyard was erected as well. This chapel is said to have housed the mortal remains of the Wise Men, although only for one night, in June 1164.
In 1306, the brothers Giacomo, Giordano and Pagano Cazanori, merchants from Blevio, built a new parish church dedicated to St. Bartholomew at their own expenses; the church was much altered over the centuries. In the end it was abandoned after the construction of a new church. Among the oldest civil buildings, note the courts of Bustigo, 'La Vigna', 'Il Caslasc' and 'La Curt Granda' which are recorded in a land register map from 1722. Although these courts have partially been renovated, they still bear witness to a country world and a Lombard folk tradition maintained intact until the end of last century. In fact, it was not until the beginning of the 20th century that Grandate grew into an industrial town (silkworm breeding, textile industry, glass and crystal manufacturing).
Among the villas, Villa Ciceri is particularly worth mentioning. It is an old palace surrounded by a large park. The villa was owned by different families such as the Canarisi, the Panigadi and the Alberti to which Mario Alberti (1884-1939), famous financial expert and economist, founder and first President of the Bank of Albania, belonged; in 1954 the villa was bought by the Benedictine Nuns who converted it into a seclusion convent. The so-called Villa Il Roccolo derives its name from a cluster of hornbeams laid out in a semicircle and originally used to net animals during hunting. The first owners were the Nessis who sold it to the Andinas. The villa is now owned by the Brunialti family. The well-known Milanese industrialist Brioschi family built an homonymous villa surrounded by a large park in the little hamlet of Borgo Purtun. The villa was then handed over to the earls Ottolenghi from Turin. Villa Borella is not so old. Built by a famous benefactor from Como, this building housed the nuns of the S. Anna Hospital. It has been recently bought by the town council and fully restored. It now houses the Town Council, the Town Centre and the public library.

Parish church of St. Bartolomeo - This building was designed by Giuseppe Malinverno and constructed in 1925-27 to replace the old deconsecrated parish church which had been converted into a civil building. From this earlier structure, a stone tablet dating back to 1306 survives and is now displayed on the false façade of the new church. In 1929 a bell tower was erected. The church was later decored.

Sanctuary of the Madonna del Noce - It has a simple triangular façade with an high relief of brickwork contained in the lunette of the portal (1970). The relief depicts a Madonna and the Child holding a walnut branch in his hands between two angels. The church was founded in the late 15th century, but it also possible that its structure is older.