Herzstück Basel is a planned underground rail tunnel through the Swiss city of Basel.

Planned since the 1980s, Herzstück Basel would provide a more direct connection between Basel Badischer Bahnhof and Basel SBB via two new underground stations, "Basel Mitte" and "Basel Klybeck".

[1] Currently, trains between the two stations take a meandering route through the city.

In 2019, the cost of the project was estimated to be 3.2 billion Swiss francs.

[2] The cantons of Basel-Stadt and Basel-Landschaft have provided 30 million Swiss francs to fund a study into the proposal.