Arnmundur graduated from the Icelandic Academy of the Arts in 2013. His film credits include THE QUIET STORM and ELEVEN MEN OUT. His TV roles include Sonur Oddu in WORLD'S END, Ulfur in THE CLIFF, National Geographic's GENIUS PICASSO, Stefan in Series 2 of TRAPPED on BBC Four and Lars Bleymann in ITV's SHETLAND. In 2017, Arnmundur was nominated for the Icelandic Theatrical Awards (Gríman) for 'Best Actor in a Leading Role' and 'Singer of the Year'. He can next be seen in A WHITE, WHITE DAY, directed by Hlynur Palmason.