Vallby is a village in Linköping Municipality, in Östergötland County, Sweden. Vallby lies at 48 m above sea level. The nearest city is Linköping, 8.6 km to the east. Among the landmarks around are Linköping Cathedral (8.1 km), Östergötland Museum (7.9 km) and Vreta Abbey (3.8 km). Among the natural features are Flistads brunn (5.1 km) and Kanberget (8.1 km).