Guldborg is a fishing village spanning the islands of Falster and Lolland in Denmark. It belongs to Guldborgsund Municipality, in Region Zealand. In 2023 the village had a population of 530, with about 500 living on the Lolland side. The village is located at the narrowest point between the two islands where Guldborg Bridge crosses Guldborgsund Sound.

Lolland is the fourth largest island of Denmark, with an area of 1,243 km2 (480 sq mi). Located in the Kattegat, Belts and Sund area, it is part of Region Sjælland. As of 1 January 2022, it has 57,618 inhabitants. Lolland is closely connected to the island of Falster to its east. The locality of Sundby forms a cross-island urban area with Nykøbing Falster, the largest conurbation partially on Lolland. The most populated settlement on Lolland proper is Nakskov.