The following is a list of episode summaries for the Sonic Underground television series. It first premiered in France on January 6, 1999 and aired on TF1 on the TF! Jeunesse block on Wednesdays and Sundays. The show later premiered in English in the UK on May 2, 1999 and aired on ITV1 on Sunday mornings. ITV1 aired the first 18 episodes in the original UK run before cancelling the show. Sonic Underground premiered in USA on August 30, 1999 and aired on the Bohbot Kids Network syndication block on weekday mornings at 6:00 AM Central Time.