Mestis (from Finnish: Mestaruussarja, meaning 'Championship series', stylized as MEST1S) is the second-highest men's ice hockey league in Finland.

The league was established by the Finnish Ice Hockey Association in 2000 to replace the I-divisioona ('First Division').

In the years 2000–2008, it was not practically possible for Mestis teams to get promoted to the SM-liiga, which was closed in 2000, but it was possible to drop down to the Suomi-sarja instead.

After the elimination of the qualifiers, Sport, KooKoo and Jukurit have been promoted to the SM-liiga through the license system.

Oy and Ab are the abbreviations for limited company in Finnish and Swedish respectively.