The site is old — local tradition reaches back much further — but the documented history of Canicattì is the history of a barony , and it is unusually well recorded because so much of it passed through notaries.

In 1393 the lord was the Agrigentine Luca Formoso , who rebelled against King Martin and was imprisoned and stripped of his property. From 1396 to 1398 it belonged to Rodrigo Fulco Palmeri; in 1400 it returned to Formoso; in 1408 it passed to Salvatore Fulco Palmeri , baron of Naro and already lord of Ravanusa, and then to his son Antonio .

The decisive transaction is precisely dated. On 12 November 1448 , by an act drawn at Girgenti before the notary Salvatore Piazza , Antonio Palmeri — a milite , the first rank of the military aristocracy, by then old, ill and without children — sold the barony for 250 onze to Andrea De Crescenzio , who had married a niece of Fulco, daughter of Filippa and Tommaso Crispo. Andrea, partly to escape dependence on his wife's family at Naro, chose to live at the Castle of Canicattì , which he enlarged and made more serviceable.

Then came the act that made the town. On 3 February 1467 he obtained from the viceroy Lope Ximenes, marquis of Urrea , acting for the king of Aragon, the casalis fines dilatandi facultas — the faculty of extending the boundaries of his casale — together with the licentia populandi , the right to receive inhabitants coming from other centres. The territory expanded toward Serradifalco, Montedoro, Racalmuto, Castrofilippo, Naro and Delia, and people were brought in to fill it.

From 1505 to 1819 the barony was held by the Bonanno , whose ruined castle still stands at the centre of the town.

The modern town took shape around a handful of buildings: the seventeenth-century Fontana del Nettuno ; the eighteenth-century Chiesa del Purgatorio and clock tower; the Renaissance Duomo of San Pancrazio at the head of its stair; and the church of San Diego on Corso Umberto, which had fallen near to ruin by the eighteenth century and was rebuilt in its present form between 1770 and 1782 , its sandstone facade added in 1865 , its bell tower in 1880 under a majolica-tiled dome, its interior decorated in stucco in 1791 .

Growth came late. The opening of the railway at the beginning of the twentieth century and the founding of several credit institutions turned Canicattì into a commercial centre for the interior; and from the 1970s the cultivation and marketing of table grapes — the uva Italia — progressively replaced the traditional almonds, cereals and legumes, and made the town prosperous enough to be counted among Italy's notable small comuni by 1987.

In recent memory Canicattì is also known for two of its own: the magistrates Antonino Saetta and Rosario Livatino , both murdered by the mafia at the end of the 1980s and the beginning of the 1990s.