Career
Viljanen made his Finnish premier division debut in June 2014 by officiating the match between Football Club Inter and MYPA. In July he was nominated as one of the referees of the 2014 Nordic Under-17 Football Championship in Denmark.
Viljanen made his Finnish premier division debut in June 2014 by officiating the match between Football Club Inter and MYPA. In July he was nominated as one of the referees of the 2014 Nordic Under-17 Football Championship in Denmark.
Viljanen was a member of the Finnish squad in the 2009 Union of European Football Associations U-21 Championship.