2008-09: Jonathan Iilahti shared the goaltending duties for the Espoo Blues U18 team with Finland U18 team backup Erno Suomalainen. In 19 games he was 9-10 with a 3.45 GAA and .898 save percentage.
2009-10: Iilahti played for the Espoo Blues junior team in Finland. At the U18 junior level, he had a 2.49 GAA and .917 save percentage in 14 games and an even better save percentage in the playoffs (.921 in 10 games). At the U18 World Championships, Iilahti's bronze-medal performance drew a lot of interest. A product of the same Espoo Blues junior program that produced Islanders' 2009 2nd-round-pick Mikko Koskinen and Suomalainen, he proved to be much more than just someone to work the bench door.
2010-11: Iilahti played six games for Kiekko-Laser in Mestis (Finland's second league) and spent the majority of the season with Espoo Blues' U20 team. Iilahti was 1-5 with a 3.84 GAA and .861 save percentage. In 18 games with Blues U20 he was 13-5 with a 2.76 GAA and .901 save percentage.
2011-12: Iilahti saw limited ice time shuffling between the Espoo Blues and Vaasa Sport clubs in Finland. He was 0-2-1 with a 3.38 goals against and .889 save percentage in four SM-Liiga games with the Blues as veterans Patrik Galbraith and Petri Koisto made the bulk of the starts. He had his best success playing with Vaasa Sport in Mestis – going 8-4 with 2 shutouts with a 1.80 goals against and .934 save percentage in 12 games. Iilahti also played goal for the Blues and Sport U20 teams. He was not tendered a contract by the Canucks in June 2012; becoming an unrestricted free agent.
Currently on loan with Sport in Mestis - also appeared in two games for Espoo Blues in SM-Liiga.