|Date of birth||15 June 1988|
|Place of birth||Helsinki, Finland|
|Playing position||Centre back|
|Current club||Kalmar FF|
|* Senior club appearances and goals counted for the domestic league only and correct as of 17 June 2013.
† Appearances (Goals).
Originally from Helsinki, Arajuuri moved to the Åland Islands and IFK Mariehamn in 2008. He had already made his debut in the Veikkausliiga with FC Honka against rivals HJK Helsinki. During his first season with IFK Mariehamn, he participated in all except two games, making it a total of 24 appearances.
During the summer of 2009, Arajuuri was frequently linked with a move to Sweden, especially to Djurgårdens IF. Arajuuri's player agent, Jonas Wirmola, admitted to one of the major newspapers of Åland that Djurgården and several other clubs had shown interest in the young Finnish defender.
Arajuuri netted his first league goals for Kalmar FF home against GAIS on 23 June 2011. He scored twice to help the Småland club earn a 2 - 1 victory. From January 1, 2014 he will play for Polish side KKS Lech Poznań.
Arajuuri has also represented Finland's U-23 national team in the International Challenge Trophy.
Arajuuri was called up to represent Finland in the U-21 national team qualifiers for the 2011 U-21 Euros. He was a part of the squad that faced Holland and Poland in September 2009, and has since that become a regular. Arajuuri earned his first cap for Finland in a friendly against South Korea on 18 January 2010 in Malaga, Spain. Arajuuri came on as a substitute in the 84th minute.
- "Fortfarande oklart kring Arajuuri-flytt". Nya Åland (Mariehamn, Finland). 20 July 2009. Retrieved 2009-07-21. (Swedish)
- "Paulus Arajuuri siirtyy Kalmariin". Veikkausliiga (Mariehamn, Finland). 24 September 2009. Retrieved 2009-09-24. (Finnish)
- "Paulus frälste Guldfågeln Arena". Kalmar FF (Kalmar, Sweden). 23 June 2011. Retrieved 2011-06-23. (Swedish)
- "U21 Suomi-Puola 3.6". Futismaailma.com (Jyväskylä, Finland). 3 June 2008. Retrieved 2008-06-03. (Finnish)
- "U23: Suomi Italian kimppuun keskiviikkona". Palloliitto.fi (Helsinki, Finland). 1 April 2008. Retrieved 2008-04-01. (Finnish)
- "Paulus representerar Finland". GMM (Helsinki, Finland). 26 August 2009. Retrieved 2009-08-26.[dead link] (Swedish)
- "Förlust för Lyyski och Arajuuri i debuten". Nya Åland (Mariehamn, Finland). 18 January 2010. Retrieved 2010-01-119. (Swedish)