London's Christmas season kicks into gear in mid-November when the Regent Street lights (organised by the Crown Estate) switch on in a ceremony that fills the street with spectators. By the first week of December, every major hotel has installed its tree, the department store Christmas windows are unveiled, and the ice rinks (Somerset House, the Natural History Museum, Kew Gardens) are open. Christmas in London is genuinely different from the rest of the year — a city that normally operates at relentless pace slows slightly, decorates grandly, and devotes itself to the season with some enthusiasm.
For hotels, Christmas is their highest-effort seasonal opportunity. Claridge's annual tree installation is perhaps the most discussed in Britain: designed by a different partner each year (Karl Lagerfeld designed one; the most recent has been Dolce & Gabbana), it transforms the lobby into a visual event that draws non-guests specifically to view it. The Ritz's lobby illumination, the Connaught's seasonal floral arrangement, and the Berkeley's chocolate advent calendar (each window reveals a different artisan chocolate made by the hotel's pastry kitchen) are all distinctive Christmas performances.
Christmas Eve dining in London is an institution at the grand hotels: the Ritz Palm Court is booked for Christmas Eve dinner months in advance; the Savoy's festive menu in the River Restaurant represents one of the most theatrical Christmas Eve settings in the country. Christmas Day in London is quieter than Paris — many restaurants and shops close, and the city takes on an unexpected stillness that long-term residents describe as one of its annual pleasures.
For practical Christmas logistics: book hotels 3–4 months ahead for December 23–January 2 stays; the ice rinks require advance booking for specific sessions during the school holidays; the Harrods and Liberty sales begin online on Christmas Day and in-store on December 27, which brings significant crowds to those areas.