Having previously played for Ireland, Sloan had to wait for three years before he was eligible to play for Great Britain. He eventually made his debut for Great Britain in April 2015 in a 3–2 win against Germany in an unofficial international. He made his official debut for Great Britain on 14 May 2015, in a 1–1 draw against Argentina. He subsequently represented Great Britain at the 2016 Summer Olympics. Sloan captained Great Britain when they won the 2017 Sultan Azlan Shah Cup. In May 2017, together with George Pinner and Phil Roper, Sloan was named as one of three captains of England/Great Britain.