Calslagen (52°14′N 4°44′E / 52.233°N 4.733°E / 52.233; 4.733) is a hamlet in the Dutch province of North Holland. It is a part of the municipality of Aalsmeer, and lies about 9 km south of Hoofddorp.
Until 1854, Calslagen (then spelled "Kalslagen") was a separate municipality, under the name of Kalslagen en Bilderdam.
The statistical area "Calslagen", which covers the hamlet and a large part of the lake area Westeinderplassen, has a population of around 550.