[1] Christiansen won three medals at the 2014 European Junior Swimming Championships.

[3] He won a silver medal at the 2016 European Aquatics Championships in the 400 metre freestyle.

[4] He turned down swimming scholarship offers from Stanford University and UC Berkeley to continue his training in Norway.

[8] In 2019, he was a member of the 2019 International Swimming League representing Team Iron.

This biographical article related to a Norwegian swimmer is a stub.