Erik Marxen (born 2 December 1990) is a Danish professional footballer who plays as a centre-back for Danish Superliga club Nordsjælland.
Marxen was born in Middelfart. He began his career in the youth academy of the local club Middelfart G&BK where he played alongside the likes of Christian Eriksen and Rasmus Falk. He eventually joined Vejle Boldklub, and made his professional debut on 13 April 2009 in a 4–1 loss in the Danish Superliga to FC Copenhagen. He came on as a late substitute for Marc Pedersen. On 10 June 2009, he signed a contract until 2011 which promoted him to the first team.