He made his full international debut in 2011 and has since gone on to make fourteen further appearances for the national side. In his youth, he first joined his local football team, Belgian Second Division side Sint-Truiden (2004), eventually rising through their youth system to become their first-choice goalkeeper in 2006 at the age of 18. In 2009, he made 29 appearances and scored a penalty in the league, helping Sint-Truiden win the Belgian Second Division, and was named Belgian Goalkeeper of the Year the following year. Between 2001 and 2010, Mignolet capped 25 times for the Belgium national U-16, U-17, U-18, U-19 and U-21 squads. In 2011, he was called up to the full national team and made ten appearances for Belgian.