The Albizzi family (Italian pronunciation: [ˈalbittsi]) was a patrician noble family and were the de facto leaders of an oligarchy of wealthy families that ruled Florence in the second half of the 14th century. They were at the center of the oligarchy from 1382, in the reaction that followed the Ciompi revolt, to the rise of the Medici in 1434.

One of the most powerful families of medieval Florence, the Albizzi were active members of the wool guild Arte della Lana and were most prosperous between the 13th and 16th centuries. The Albizzi were known for their opposition to the Medici family and their significant role in the city's political and social life.

The Albizzi moved to Florence from Arezzo sometime in the 12th century, and rose to power during the 14th century through their increasing influence over Florentine politics and bureaucratic offices, and their multiple businesses. The family held a strong position in the wool guild, often contributing to shaping the guild’s governing policies and laws. Guild records have also shown the Albizzi to be among the most active in the governing of the Arte della Lana, as shown by the significant number of its members in the guild’s cabinet (21 in the year 1332 and 18 in the year 1353). By the beginning of the Trecento, the Albizzi had established themselves as one of the most prominent families of Florentine nobility, owing to their success as merchants and financiers.

The Albizzi family’s main business was the production, refinement, and commerce of wool. While they did trade in and around Florence, their most prolific markets were Venice, Flanders, and England. The business was run in a fondaco (warehouse) and two bottege (shops). In addition to producing and selling cloth, the Albizzi also started granting loans to other families and businesses and sold and rented land, fulling mills, and factories located in Tuscany. The Albizzi were also directly involved in governing Florence and in particular their own neighborhood.

By the 1360s, two rival factions had emerged in Florence: the Albizzi family, who supported and favored alliances with the Papacy and Naples, and the Ricci family, who pushed for more representation for the common people. These factions fought until 1372, when the Signoria banned the Albizzi from holding public office for five years. During this ban, Maso degli Albizzi, a prominent member of the family, was removed from his position in Pistoia, a region controlled by Florence. However, his setback was brief. After the Ciompi Revolt ended in 1382, Maso returned to power.

The Albizzi family regained control of the city after a difficult and often violent period. This turmoil followed the War of the Eight Saints (1375 - 1378), a failed military campaign against the Papacy that drained Florence’s finances and imposed harsh religious penalties on the population, leading to widespread dissatisfaction with the government. In the aftermath of the Ciompi Revolt, an oligarchic regime took over Florence. This regime, dominated by the city’s wealthy patricians who controlled both commerce and government decisions, was led by Maso degli Albizzi.

During the Albizzi rule after the Ciompi riots, promotions and other forms of sponsorship played an important role in strengthening their influence in Florence. In particular, from 1382 to 1392, ceremonies and events such as chivalric-courtly celebrations were arranged by the Albizzi to boost their public image and social relations with other powerful families. After 1390, however, they increasingly included joust and tournaments, although these were less common. Another way the Albizzi established strong political connections was by welcoming important guests into their private homes. These guests were given special treatment, often watching events from prime spots like church steps or windows, or even participating as spectators or contenders, all while being comfortably accommodated nearby.

One of the greatest reasons for the Albizzi’s popularity lies in the famed portrait of Giovanna degli Albizzi Tornabuoni by the artist Domenico Ghirlandaio. Giovanna’s portraits became an iconic paradigm of Renaissance art, thus exemplifying the Albizzi family’s, including Giovanna’s, role in supporting the arts, contributing to Florence's cultural legacy.