The Lapland airports in northern Finland also achieved their one million passenger milestone earlier in the year than ever before.
Passenger numbers for the entire country increased 10.8 percent in December 2017 and 9.2 percent for the whole of 2017.
European Union passengers represented more than 71.4 percent of all scheduled flight passengers. However, passengers from Japan, China, Russia and Hong Kong saw the largest growth at Helsinki Airport.
Joni Sundelin, senior vice president, sales and network, Finavia, said that the company is discussing new routes, additional flights and the use of larger aircraft with a number of airlines.