The first church of Sant'Andrea in Castelletto Val di Tolla was built in 1167 by Alberto, Abbot of the Monastery of San Salvatore di Val Tolla, who chose for this purpose a dominant panoramic position, on the edge of an ancient road that ran along the entire right side of the valley from Vitalta to Pelizzone.
The church of Abbot Alberto carried out its function for over four centuries, but in 1618 the old church was seriously unsafe and was banned, the parish priest transferred elsewhere and the parishioners of Castelletto authorized to go to mass in the neighborhood parishes.
The people of Castelletto evidently could not accept this situation and, in the autumn of the following year, once the harvest work was finished, they began to build a new church in the same location, thirty-five steps away from the previous one.
The new church was ready on 2 December 1619 and was blessed in February 1620.
The sacristy was built in 1775 and the bell tower in 1777.
In 1885 the population of Castelletto had exceeded 400 units and the church was no longer able to accommodate all the faithful: it was therefore enlarged with the addition of a front bay and an extension on the right side.
It was deconsecrated in 1947 following the construction of the current new church within the town.