Lallio is a comune located in the Province of Bergamo within the Lombardy region of northern Italy. It is situated approximately 5 kilometres (3.1 mi) southwest of Bergamo and about 45 kilometres (28 mi) northeast of Milan.
As of December 31, 2004, the municipality covered an area of 2.1 square kilometres (0.81 mi2) with a population of 4,050 residents.