Lamongan Regency is a regency located in the East Java Province of Indonesia. It covers a total land area of approximately 1,812.8 km² (699.9 sq mi), which accounts for more than 3.7% of the province's total area. The region also features a coastline extending 47 km (29 mi) along the sea.
The regency seat is the town of Lamongan, which is situated on the Solo River. This river flows from west to east through the regency, effectively dividing the territory into two sections. As of mid-2024, the official population estimate for the regency is approximately 1,367,503 people.