IFK Norrköping
In 2017, IFK Norrköping reached the final of Svenska Cupen, the main domestic cup, but lost 1–4 against Östersunds FK. During the summer transfer window, Fjoluson reportedly attracted interest from Turkish club Konyaspor, but IFK Norrköping declined an offer of 5 million Swedish kronor. IFK Norrköping finished 6th in the Allsvenskan table and Jón ended the season by playing all 30 league games.