Eurostar is raising capacity to the Continent over the festival season as travel demand continues to rise.
Sales for additional trains between the UK and mainland Europe have opened.
The Christmas timetable will operate from December 12 until January 8.
This will include nine daily return services on weekdays between London and Paris, five returns between London and Brussels and two between London and Amsterdam.
Fares start at £39 one way.
The easing of travel restrictions has seen a surge in demand for travel with September bookings quadrupling over the same period last year.
The high-speed rail operator will run 15 services on October 22, set to be the busiest day this year, as travellers make the most of autumn school half-term holiday.
Passengers must wear a mask on board and in stations. This continues to apply after check-in at London St Pancras.