Sinj area was inhabited in prehistoric times. The archaeological founds confirmed the so-called Cetina culture. In the Bronze Age the natives came, members of the Illyrian tribe Delmata who are continuing its development until the arrival of the Romans.
After the fall of the Roman Empire in the 7th century, Sinj was inhabited by Croats who received Christianity through Franks. After the formation of the Croatian kingdom, Sinj as a fortified town was the seat of the Cetina County. The knights of Cetina get stronger in the time of rulers Šubić and from 1345 Nelipić.
Frequent Turkish attacks have led to the fall of the city in 1513 but in 1686 Sinj is under Venetian rule. Nevertheless, the Turks do not give up: still trying to conquer Sinj, in 1715 the most important battle held when 700 people of Sinj defended a city from tens of thousands of Turks. Weakened by hunger and dysentery, Turks have left the Cetina region, and local people are being rescued.
By 1797 Sinj was again under Venetian rule, until 1918 under Austria, and in the 20th century, as well as the rest of Croatian, in two Yugoslavias to the final creation of the Croatian Republic.