Jon Michael Kleinberg (born 1971, Boston) is a Professor of Computer Science at Cornell University. He received his B.S. from Cornell in 1993 and his Ph.D. from MIT in 1996. His current research is focused on the mathematical analysis and modeling of the combinatorial structure of networks and information. His recent work includes an improvement to the HITS algorithm which he developed at IBM's Almaden Research Laboratory as a Visiting Scientist in the CLEVER project. HITS is a very influential algorithm of his, conceptually similar to the PageRank algorithm of Larry Page and Sergey Brin. In fact, some credit Kleinberg's work as the inspiration for PageRank.

Many students affectionately call him the "Rebel King" (an anagram for "Kleinberg"). The "Rebel King" phenomenon began in an undergraduate course taught by Jon Kleinberg, when an unknown student entered the lecture hall in the middle of the class, announced in a loud voice that "Kleinberg is Rebel King," and then promptly left the lecture hall. The "Rebel King" tradition continued in subsequent years, when subsequent classes taught by Jon Kleinberg received similar visits from an unknown student who again announced loudly that "Kleinberg is Rebel King" before making a rapid exit. While co-teaching a class with Eva Tardos students also made an anagram of her name "Astro Dave" which has not caught on. The most recent of these incidents occurred on |March 9, |2007 when two unknown students, shirtless and adorned with red paint,entered the lecture hall of Kleinberg's class on network structures, chanted "Long Live the Rebel King" and ran out another exit. Kleinberg's popularity among students is due in part to his excellence in teaching, which was formally recognized when Cornell's Association of Computer Science Undergraduates awarded him the "Faculty of the Year" award in 2002.

He has written numerous prominent papers and articles, including a recent textbook on algorithms, Algorithm Design, co-authored with Éva Tardos and published by Addison-Wesley.

His work has been supported by an NSF Career Award, an ONR Young Investigator Award, a MacArthur Foundation Fellowship, a Packard Foundation Fellowship, a Sloan Foundation Fellowship, and grants from the NSF. He received the Nevanlinna Prize in 2006.