Leader made his first 2013–14 Pro12 appearance on 2 November 2013 against the Glasgow Warriors, which was his first game for the senior team in over a year, as well as his first game at the Sportsground. He started the match at outside centre, and played for the full 80 minutes. Leader made his first European appearance on 14 December 2013 at home to Toulouse in the 2013–14 Heineken Cup, coming on as a replacement. His first start in the competition came against Zebre on 11 January 2014 in a 20-3 win. Leader finished the season with 13 appearances in the league, seven of these coming as starts, and scored two tries. His first ever try for the province came in a derby with Ulster.