There are three hypotheses about the village's name, and the most convincing is also the first thing ever written about this place. On the twenty-fifth of September 758 a deed records the passing, among some nobles of Lombard origin, of a wood made up largely of hornbeams: and Carpaneto should come precisely from there, from the tree. The second hypothesis brings in the Latin carbonetum, a coal store, because the village was for centuries a trading place for cereals and for charcoal, got on the mountains Menegosa, Lama and Pelpi and brought down here by mules along the val Chero, which for that reason was called the coal road; the third would have the name come from a founder, one M. Carbo who lived before Christ. The adjective Piacentino was added in 1929. Curious, instead, is the position of the old coat of arms, which did not choose: besides the hornbeam plant it put in a castle and a lake full of carp, keeping two different etymologies in play at once.
The castle is still there, and it is the town hall: in 1908, some years after the death of count Carlo Scotti — who had also been the comune's mayor — the family sold it to the local authority, which moved the offices in and did away with the rooms until then used as stables. All the rest of the defences has gone: between the nineteenth and twentieth centuries the fortifications were pulled down, the moat was filled, and in the end the arch of via Roma fell too, that is the entrance to the village for those arriving from Piacenza, which carried the arms of the Scotti Douglas above it. Between 1941 and 1943 Carpaneto was one of the Emilian comuni used as a place of free internment for foreign Jews: here the four members of the Nichtberger family, of German-Polish origin, lived under forced residence, having arrived in Italy as refugees the year before. With the German occupation they were arrested on the thirtieth of November 1943, taken to the camp of Fossoli and then to Auschwitz, where they died. In the village, in their memory, memorial stones have been laid.