Midden-Delfland is a municipality in the Westland region in the province of South Holland in the Netherlands. It had a population of 19,391 in 2019, and covers an area of 49.38 km² of which 2.19 km² is water.
It was formed on January 1, 2004, through the merger of the former municipalities:
Maasland, covered an area of 24.42 km² of which 0.6 km² water.
Schipluiden, covered an area of 30.00 km² of which 0.39 km² water.