The 2017–18 Liiga season was the 43rd season of the SM-liiga (branded simply as "Liiga"), the top level of ice hockey in Finland, since the league's formation in 1975. Tappara was the season as a defending champion. This season included a record number of matches played on Fridays and Saturdays. In autumn, there was a national team break from 5 November until 13 November. Kärpät won the championship by winning Tappara in the final series 4-2.