Joachim Thomassen (born 4 May 1988) is a former Norwegian footballer.

In January 2008, he joined Fredrikstad and played his first game for the club against Kongsvinger.

In May 2009, he signed a contract extension for Fredrikstad until 2012.

In November 2011, he was rumored to join the Seattle Sounders FC of Major League Soccer.

This biographical article related to a Norwegian association football defender is a stub.