The origins of Santo Stefano d’Aveto sink roots into a very ancient past, which probably dates back to prehistoric times. Thanks to its strategic position, at the crossroads of different territories and cultures, the village soon became a point of reference for the entire Val d'Aveto, in particular for the Ligurian populations that inhabited these mountains. According to some historical sources, right on the slopes of the Mount Penna one of the last battles of the Roman Empire for control of the region would be fought.
Starting from the Lombard era, the territory came under the influence of the monks of the’Order of Saint Columbanus, tied to the famous abbey of Bobbio, who also founded the monastery of Torrio, leaving a profound mark on the spiritual and cultural life of the valley.
Nel 12th century, the history of Santo Stefano d'Aveto is intertwined with that of the great feudal families. In 1164 the emperor Frederick Barbarossa he entrusted the fief and the entire valley to Malaspina, which transformed the village into an important defensive stronghold, building fortifications and castles. Among these, the striking one still stands out today Malaspina Castle, which dominates the country and tells the story of its glorious past.
At the end of the 15th century, the fiefdom passed to Fieschi, counts of Lavagna, whose lordship was confirmed by the emperors Maximilian I and Charles V. But in 1547, following the famous Fieschi conspiracy against the Doria of Genoa, the territory was confiscated and assigned to Andrea Doria, thus entering the domains of Republic of Genoa. From 1649 the fiefdom passed to the family Doria Pamphilj, whose administration was often poorly tolerated by the local population.
The discontent turned into a real popular insurrection in 1796, one of the most dramatic episodes in local history, which marked the end of feudal lordship in the village.
With the arrival of Napoleon Bonaparte, Santo Stefano d'Aveto became part of Ligurian Republic and subsequently of the French Empire, experiencing years of profound administrative transformations. After the Congress of Vienna in 1815, the country was incorporated into the Kingdom of Sardinia, and then definitively enter the Kingdom of Italy in 1861.
During the nineteenth and twentieth centuries, the territory continued to evolve, redesigning its administrative boundaries and strengthening its bond with its hamlets and the entire valley. From 1973 to 2011, Santo Stefano d'Aveto was part of the Mountain Community of the Aveto, Graveglia and Sturla Valleys, confirming its central role in the mountain life of the Ligurian hinterland.