Gnarr and Sigurjon Kjartansson formed the radio and television duo Tvihofoi in 1994. He has starred in films and in stand-up comedy specials and is a member of the Icelandic Actors Guild and the Playwrights and Screenwriters Guild. Gnarr authored the book Gnarr!: How I Became the Mayor of a Large City in Iceland and Changed the World. In 2015 he joined Rice University’s Center for Energy and Environmental Research in the Human Sciences as a writer.