Barrett played for the senior Canadian national basketball team. With Canada, he played at the 1998 FIBA World Championship, the 2000 Summer Olympic Games, and the 2002 FIBA World Championship. He also played at the 1993 FIBA AmeriCup, the 1997 FIBA AmeriCup, the 1999 FIBA AmeriCup, and the 2003 FIBA AmeriCup.