Ball, 24, has played his entire career in Charlotte and has three years remaining on the five-year, $260-million max contract he signed with the Hornets.
Over 72 games last season, Ball averaged 20.1 points, 7.1 assists and 4.8 rebounds over 28 minutes a game.
The Hornets were knocked out in the NBA play-in tournament, and may be looking to shift away from Ball as the focal point of the team and instead build around rising stars Brandon Miller and Kon Knueppel.
Meanwhile, the Raptors headed into the summer with a need at guard, and Ball certainly has the talent to fill a hole on the Toronto roster.