In 1624, a Franciscan Mission established a reduction for the indigenous tribes of the area named Santo Domingo Soriano. In spite of interruptions in its existence, it is considered the earliest populated centre of the actual Uruguay. Eventually, in its place Villa Soriano was founded.
The first division of Uruguay in departments happened on 27 January 1816. At the time, eight departments were formed, with Soriano being one of them. When the first constitution was signed in 1830, Soriano Department was one of the nine original departments of the Republic.