Sønderup is an urban Settlement in Slagelse Municipality, in the region of Zealand, Denmark. Sønderup lies at 24 m above sea level. It has 202 inhabitants (2026). The nearest city is Slagelse, 6.6 km to the southwest. Beaches nearby: Mullerup (14 km). Among the landmarks around are Trelleborg (10.5 km), Sorø Art Museum (11.5 km) and Antvorskov (8.0 km).