Sorengo is first mentioned in 1189 as Sourengo when the S. Lorenzo Cathedral in Lugano acquired the right to collect tithes.
In the Late Middle Ages a number of groups owned land or rights in Sorengo including; the monastery of S. Abbondio in Como (from 1265), Como Cathedral (mentioned in 1298), and various important family, including the Torriani and Rusca. Sorengo was first mentioned as an independent municipality in 1298, and the settlement of Cortivallo had partial independence into the 18th Century. Sorengeo alternated with Lugano and Loreto as the meeting place of the General Council of the city and valley of Lugano. It was used by the Council in the 16th Century, in 1687 and again in 1696.
The inhabitants of Sorengo were part of the parish of Lugano, until 1776 when they became a separate parish. The church of S. Maria Assunta dates back to about the end of the 11th Century back, but is not mentioned until 1298. It was expanded in 1566-1593, then rebuilt several times, and renovated in 1975-76 and 1980-81. In 1565 some monks from Bigorio founded a Capuchin monastery by the church, which moved in 1653 to Lugano and is now known as SS. Trinità Monastery.
Since the 1950s, Sorengo has transformed from a rural village into a commuter town for the agglomeration of Lugano. Several organizations have settled in Sorengo including; the children's charity Opera per l'assistenza alla ticinese fanciullezza (since 1920), the S. Anna Hospital (since 1934) and the American private university, Franklin University Switzerland (since 1986). In 2005, 96% of jobs in the municipality were in the services sector.