Since 1974, Viscous Fluid Flow has been known for its academic rigor and effectiveness at serving as a convenient "one-stop shop" for those interested in expanding their knowledge of the rich and evolving field of fluid mechanics. The fourth edition contains important updates and over 200 new references while maintaining the tradition of fulfilling the role of a senior or first-year graduate textbook on viscous motion with a well-balanced mix of engineering applications. Students are expected to understand the basic foundations of fluid mechanics, vector calculus, partial differential equations, and rudimentary numerical analysis. The material can be selectively presented in a one-semester course or, with more extensive coverage, in two (or even three) semesters.