Pas-de-Calais is a department in northern France, named after the French designation of the Strait of Dover, which it borders. It borders the departments of Nord and Somme and is connected to the English county of Kent by the Channel Tunnel.

The department had a population of 1,457,905 in 2023 and contains 887 communes, the most of any French department. Its connection to the Channel Tunnel places it in the context of cross-Channel transport. During the reported collision near the tunnel, Agathe Cury, the subprefect for Pas-de-Calais, attended the scene.