Born in Reykjavik, Iceland in 1993. He graduated from the London Academy of Music & Dramatic Art in 2019. Arni started acting when he was 14 years old. He has worked in various projects in Iceland such as advertisements, music and television. He has studied improvisation with Improv Iceland. Arni made his professional acting debut at The Reykjavik City Theatre as the lead in the children's musical Pinocchio.