Gunter received his first call up to the senior international side at the age of seventeen for a friendly match against New Zealand at the end of his first season of professional football, describing himself as being "absolutely staggered". He made his debut for Wales in the match on 26 May 2007 at the Racecourse Ground, Wrexham, featuring for the first half of a 2–2 draw. He was ever present at right back during 2010 World Cup qualifying and was the only player in the squad to have played in all ten matches.