Season 4

Season 4 of premiered on October 4, 1999  on PBS. This was the first season in which only 10 episodes (20 segments) were produced per season, a pattern that would not be broken until Season 20.

This is the last season to feature voice actors Oliver Grainger and Luke Reid as D.W. and Brain, respectively. Head writers Joe Fallon and Ken Scarborough also left the team after this season, though Scarborough would return as a writer starting in Season 9.