Eurostar carried more than 10 million passengers in 2013, the first time it has reached the milestone since it launched 20 years ago.
Revenues from ticket sales rose 7% to £857m for the year and operating profit was up 4% to £54m.
Eurostar said sales were boosted by a rise in business travel between the UK and continental Europe.
"After a period of economic uncertainty, we are now starting to see more confidence in the business market," said chief executive Nicolas Petrovic.
"In comparison with this time last year, when the overriding sentiment was still very cautious, there are more encouraging trends, and in some sectors, there is clearly a greater appetite to invest and look for business."
Revenues from business traffic were up by 6.2% year on year.
