Datahold will manage all aspects of the company's database. The data firm already manages the capture and collation of Viking River Cruises on-board questionnaires.
Jed Mooney, managing director of Datahold, said: "Viking River Cruises is one of the most prestigious brands in the world cruise industry.
"We're thrilled to have been chosen to manage its UK database and also to be given the responsibility of making recommendations based on our knowledge and expertise."
Viking River Cruises was founded in 1997 and claims to be the largest river cruise company in the world, with a fleet of 21 deluxe ships and offices worldwide.