William Dale Wittliff, sometimes credited as Bill Wittliff, was an American screenwriter, author, and photographer who wrote the screenplays for The Perfect Storm (2000), Barbarosa (1982), Raggedy Man (1981), and many others.

The Perfect Storm is a 2000 American disaster drama film directed by Wolfgang Petersen and based on the 1997 creative non-fiction book of the same name by Sebastian Junger. The film was adapted by William D. Wittliff, with an uncredited rewrite by Bo Goldman, and tells the story of the Andrea Gail, a commercial fishing vessel that was lost at sea with all hands after being caught in the Perfect Storm of 1991. The film stars George Clooney, Mark Wahlberg, Diane Lane, William Fichtner, Karen Allen, Bob Gunton, Mary Elizabeth Mastrantonio, and John C. Reilly.