Internationally, De Rosario represented the Canadian national team from 1998 to 2015 where he is their all-time leading scorer, with 22 goals in 81 games. De Rosario is a 2000 CONCACAF Gold Cup champion and four-time Canadian Player of the Year. As part of the Canadian Soccer Association's 2012 centennial celebration, he was honoured on the all-time Canada XI men's team.