Harley Jessup (born 1954) is an American production designer and visual effects art director who has been nominated for two visual effects Academy Awards, and won once. Currently working at Pixar Animation Studios, Jessup has served as production designer for Monsters, Inc. (with Bob Pauley), Ratatouille, Cars 2, Presto, The Good Dinosaur and Pixar's animated feature, Coco. Before coming to Pixar, Jessup was production designer on Walt Disney Pictures' James and the Giant Peach.

Jessup was a visual effects art director at Industrial Light & Magic from 1987 to 1994. From 1991 to 1994 he served as ILM art department creative director. Jessup's visual effects art direction credits include, Innerspace (for which he won an Academy Award), Hook (nominated for an Academy Award), The Hunt for Red October (with Steve Beck), Ghostbusters II, Joe Versus the Volcano and Fire in the Sky.

In 1985, Jessup won an Emmy Award for best visual effects for The Ewok Adventure, produced by Lucasfilm, Ltd. for ABC Television.

Harley Jessup began his career at Korty Films designing animated short films for Sesame Street, including The Adventures of Thelma Thumb. He served as art director on John Korty's animated feature Twice Upon a Time.

Jessup has written and illustrated three children's books, What Alice Up to? and Grandma Summer for Viking Children's Books and Welcome to Monstropolis for Disney/Egmont. He studied graphic design at Oregon State University (BFA) and Stanford University (MFA).