Joi Johannsson (born Jóhann G. Jóhannsson, 23 November 1971, Reykjavík, Iceland) is an Icelandic actor, producer, and writer. He made his acting debut in 1986 in the TV mini-series Nonni and Manni and graduated magna cum laude from the University of Hartford in 1994 with a B.A. in Theatre and Cinematic Arts. He is multilingual — fluent in Icelandic, English, German, Danish, Norwegian, and Swedish — and has performed in nearly 50 theatre productions across the USA and Iceland, including A Winter's Tale (as Leontes) and One Man, Two Guvnors (as Stanley). He has also hosted, produced, and written over 200 TV episodes and 150 radio shows. His screen filmography spans more than 50 international productions. Notable credits include Flags of Our Fathers (2006), The Shamer's Daughter (2013), The Deep (2017), The Oath (2019), His Dark Materials (2019), Fortitude (2020), True Detective (2024), and Eurovision Song Contest: The Story of Fire Saga (2020). His most recent roles include Fractures (2022), Útilega (2024), The Fires (2025) as Kristinn, and The Brink of War (2026) as a KGB Colonel. He won the 2026 Edda Award for Best Supporting Actor for The Fires.