Jackson qualified for Canadian citizenship by virtue of his years of residence there as a child, and currently has 45 caps for Canada, scoring six times. He also has seven caps for the Canadian men’s youth (under-20) team. His first game was a friendly against Brazil in May 2006, and he played in all three of Canada’s games at the 2007 FIFA U-20 World Cup, his last games at that level. On 14 November 2008, he received his first call up for the Canadian senior squad for a match against his country of birth, Jamaica.
On 30 May 2009, Jackson made his debut for Canada against Cyprus, scoring the winning goal in the 53rd minute of a 1–0 victory. Jackson helped Canada reach the quarter-final stage of the 2009 CONCACAF Gold Cup in the USA, playing in all four of Canada’s games in the tournament. On 18 December 2009, Jackson was named the 2009 Canadian Player of the Year.
National team coach Stephen Hart decided in the friendly versus Peru to experiment by using Jackson as a right winger. With a solid performance at BMO Field Hart continued to use Jackson out wide for future Canada match ups. On 8 October 2010, Jackson scored his second international goal with a chip in a friendly against Ukraine. On 7 October 2011, Jackson scored a hat-trick against Saint Lucia in a game that finished in a 7–0 away victory for Canada. Jackson became only the second ever Canadian to score a hat-trick in World Cup qualifying joining the former striker Alex Bunbury. In early December, Jackson was short listed for the 2011 Canadian Player of the Year along with Dwayne De Rosario and Josh Simpson, it was announced on 14 December that he had finished in second place losing out to De Rosario.
In the summer of 2013, Jackson was selected for his third consecutive Gold Cup, but after playing in the first group stage game against Martinique he left with the team’s blessing to join his new German club and was replaced by Kyle Porter for the remainder of the tournament.