Pordenone was created in the High Middle Ages as a river port on the Noncello, with the name Portus Naonis. In the area, however, there were already villas and agricultural settlements in the Roman age.

In 1278, after having been administrated by several feudatories, the city was handed over to the Habsburg family, forming an Austrian enclave within the territory of the Patriarchal State of Friuli. In the 14th century, Pordenone grew substantially due to the flourishing river trades, gaining the status of city in December 1314.

In 1508, after the failed invasion of the Republic of Venice by Emperor Maximilian, the city was seized by Venice. Despite temporary Austrian occupation during the subsequent War of the League of Cambrai (1509-16), the Venetian sovereignty over Pordenone was confirmed in 1516. Until 1537, the town was ruled by the feudal family d'Alviano, as a reward for Bartolomeo d'Alviano's military service to the Republic. Under Venice a new port was built and the manufacturers improved.

After the Napoleonic period, Pordenone was included in the Austrian possessions in Italy (Kingdom of Lombardy-Venetia). The railway connection, including Pordenone railway station (1855), and the construction of the Pontebbana road brought on the decline of the port, but spurred substantial industrial development (especially for the working of cotton). Pordenone was annexed to Italy in 1866.

The cotton sector decayed after the damage of World War I and failed completely after the 1929 crisis. After World War II, the local Zanussi firm became a world giant of household appliances, and in 1968, Pordenone became capital of the province with the same name, including territory belonging to Udine.

After World War II, Pordenone, as well as the rest of Friuli-Venezia Giulia, became a garrison for many military units, in order to prevent a socialist Yugoslavian invasion from the east.

The heavy military presence boosted the economy of the once-depressed area.

Pordenone is as now garrison of the 132nd Armored Brigade "Ariete".