London is served by the ports of Southhampton, Harwich, and Dover, but isn't a cruise port. Together, the cruise port of Southhampton, Harwich, and Dover is the seventh most departed-from cruise terminal in the world, departure point of around three hundred and twenty-five cruises per year from Cunard, Norwegian, Royal Caribbean and more to Europe, the East Coast, and the Caribbean.
Overall London is fairly expensive compared to other ports. The illustration below shows the monthly average cost per day for cruises from London. Sailings departing from London during the the peak season of summer are considerably more expensive than the the low season of winter.