Nykøbing Falster is a city on the island of Falster in southern Denmark. It has a population of 16,636. Including the satellite town Sundby on the Lolland side, with a population of 3,233, the total population is 19,869. Nykøbing Falster is the seat of the Guldborgsund kommune in Region Sjælland. The city lies on Falster, and is connected by the 295-metre-long Frederick IX Bridge over the Guldborgsund waterway to the island of Lolland.