Dunford was born in Dungarvan, County Waterford, Ireland. He graduated from the Gaiety School of Acting in June 2009. He began his acting career in 2010 on The Tudors. He also appeared on An Crisis and Game of Thrones. In 2015, he received an IFTA in the category of Best Actor in a Lead Role in Film for his part in Patrick's Day. That same year he also received an EEP Shooting Stars Award representing Ireland at the Berlin Film Festival. In 2016, he received an IFTA in the category of Best Actor in a Supporting Role in TV Drama for Vikings.