The Klampenborg Line is a railway line between Copenhagen and Klampenborg in the northern suburbs of Copenhagen, Denmark. It is the shortest of the six radial lines of Copenhagen's S-train network, a hybrid commuter rail and rapid transit system serving Greater Copenhagen.

The Copenhagen S-train, the S-train of Copenhagen, Denmark, is a key part of public transport in the city. It is a hybrid urban-suburban rail serving most of the Copenhagen urban area, and is analogous to the S-Bahn systems of Berlin, Vienna and Hamburg. The trains connect the Copenhagen inner city with Hillerød, Klampenborg, Frederikssund, Farum, Høje-Taastrup and Køge. There are 170 km (110 mi) of double track with 87 S-train stations, of which eight are in neighbouring towns outside greater Copenhagen.