Nicholas Arnesson (Old Norse: Nikolás Árnason) (ca. 1150 – 7 November 1225) was a Norwegian bishop and nobleman during the Norwegian civil war era. He was a leader in the opposition against King Sverre of Norway and founder of the Bagler party. He is a chief antagonist in Sverris saga. and also appeared in The Pretenders, an historic drama written by Henrik Ibsen in 1863.