Skällberget is a prehistoric hillfort in Siuntio in Uusimaa region, Finland.

The archaeological site, located across the road from the medieval St. Peter's Church, is protected by law.

The hillfort consists of a small area on top of Skällberget Hill with a protective wall built of stones and ground on the southern side of the hill.

The eastern part of the hill consists of steep cliffs.

It is believed that the fort functions as a guard post or a refuge site in a case of an hostile attack to the area.