Hamburg-Köln-Express GmbH (HKX) was a Cologne-based open-access train operating company providing long-distance railway passenger services in Germany.

After Keolis withdrew its applications in April 2010, a framework contract was signed in June 2010 with a planned expiry date of December 2015.

[3][8] The Hamburg-Köln-Express called at most intermediate stations also served by DB long-distance trains, but left out Düsseldorf Airport and Bremen Hbf.

On 14 March 2012 Veolia Verkehr, a subsidiary of Veolia-Transdev, signed an agreement to operate the services under contract to HKX.

Eva Kreienkamp, CEO and CFO, was responsible for business development, strategy, marketing, sales and communication, finances, controlling, legal issues, purchase, and human resources, and was also managing director, RDC Deutschland GmbH.