It is not known when the city was first inhabited, but it is believed that it was built by the Macedonian army during the reign of Alexander the Great. The town was known as Saltus in Byzantine times and was the seat of abishopric. At this time, the town was considered to be the principal settlement on the East Bank of the Jordan River. The settlement was destroyed by the Mongols and then rebuilt during the reign of the Mamluksultan Baybars I (1260–1277) and became a regional capital once more during the time of the Ottoman Empire. In the early 1830s, Salt was again attacked, this time being blown up during a raid by the Egyptian viceroy brahim Pasha in his campaigns against the Ottomans in Palestine.
Salt's heyday was in the late 19th century when traders arrived from Nablus to expand their trading network eastwards beyond the River Jordan. As a result of the influx of newcomers this period saw the rapid expansion of Salt from a simple peasant village into a town with many architecturally elegant buildings, many built in the Nablusi style from the attractive honey-coloured local stone. A large number of buildings from this era survive as of 2009.
After World War I, the town was the site which Herbert Samuel, British high commissioner for Palestine, chose to make his announcement that the British favoured a Hejazi Hashimite ruled entity in the East Bank of the Palestine mandate (modern Jordan) (which was granted in 1921).
When Prince Abdullah I rose to power, Salt seemed to be the city that would be chosen as the capital of the new kingdom since most of the industry and commerce flowed through here. Salt had no high schools. Prince Abdullah 2 picked the city as the capital of his emerging emirate but changed his mind and moved his compound and entourage to Amman when he and the notables of Salt had a disagreement. Amman which was a small city of only 20,000 people experienced rapid growth
