Eventually, Arajuuri signed a four-year deal on a Bosman-transfer with the Swedish champions of 2008, Kalmar FF on 24 September 2009. He netted his first league goals for Kalmar FF at home against GAIS on 23 June 2011. He scored twice to help the Småland club earn a 2–1 win. Arajuuri played a total of ten matches during the 2011 Allsvenskan, nine of them in the starting line-up, as he scored two goals. Kalmar finished eighth in Allsvenskan, as they advanced to the final of the Svenska Cupen which was lost to Helsingborgs IF. However, through their cup final participation, Kalmar qualified for the UEFA Europa League qualifiers.