David Anthony Watt (born 1946 is a British computer scientist.
Watt is a professor at the University of Glasgow, Scotland. With Peter Mosses he developed action semantics, a combination of denotational semantics, operational and algebraic semantics. He currently teaches a third year programming languages course, and a postgraduate course on algorithms and data structures.  He is recognizable around campus for his more formal attire compared to the department's normally casual dress code.