The Den Helder–Amsterdam railway is a railway line in the Netherlands running from Den Helder to Amsterdam, passing through Alkmaar and Zaandam.

It is also called the Staatslijn K ("state line K") in Dutch.

The line is 81 km long.

[1] The following stations are on Staatslijn K: The line began construction on 18 August 1860 and on 18 December 1865 the first section opened.

The sections were opened on: The line between Alkmaar and Amsterdam was electrified in 1931 and between Den Helder and Alkmaar in 1958.