Kaniehtiio Horn (also credited as Tiio Horn) is a Canadian actress best known for her starring role as Monica Bellow in the television sitcom 18 to Life.
She is also known for her recurring role as Rynn, an Irathient warrior who is one of the Spirit Riders, in the science fiction television series Defiance.
Born in Notre-Dame-de-Grâce, Montreal, Quebec, Canada, Horn is a Mohawk actress. In only her eighth outing as an actress she was nominated for a Gemini Award for her role in the television film Moccasin Flats: Redemption.
Her mother, Kahn-Tineta Horn, is a former model and a political activist for the Kahnawake First Nation. Her father, a lawyer, is Caucasian (of German/Scottish descent).
Horn is a native of Kahnawake, a Mohawk reserve outside of Montreal, and is the youngest of seven sisters. One of her sisters, Waneek Horn-Miller, was a member of the Canadian Women's Water Polo Team that won a Gold Medal at the 1999 Pan-Am Games in Winnipeg, and was also co-captain of the Canadian women's water polo team at the 2000 Sydney Olympics.
She graduated from Dawson College in 2005 for Theatre arts and appeared in a number of short films and TV movies before her bit part in 2008's Journey to the Center of the Earth.
Several roles followed in the following years, leading to her latest work, as the Mohawk mother of the main character (Conner) in the Computer Game Assassin's Creed 3. For this role her real name was used for her character's name.
In 2013 she had a major recurring role on the fantasy series Hemlock Grove.