Raja Gosnell Director Freddie Prinze Jr. Freddy Actor Sarah Michelle Gellar Daphne Actor Matthew Lillard Shaggy Actor Linda Cardellini Thelma Actor Seth Green Patrick Wisely Actor Peter Boyle Jeremiah Wickles Actor Tim Blake Nelson Jacobo Actor Alicia Silverstone Heather Jasper-Howe Actor Neil Fanning Scooby-Doo Voice Pat O'Brien Self Ruben Studdard Self Bill Meilen Chauffeur Actor Zahf Paroo Ned Actor William Hanna Writer Joseph Barbera Writer, Executive Producer James Gunn Screenwriter Richard Suckle Producer Charles Roven Producer Brent O'Connor Executive Producer Kelley Smith-Wait Executive Producer Oliver Wood Cinematographer Kent Beyda Film Editing David Newman Original Music Bill Boes Production Design Don Macaulay Art Director Michael N. Wong Art Director Ted Kuchera Set Decoration Leesa Evans Costume Design Mary Vernieu Casting