John Kenneth Ousterhout (, born October 15, 1954) is the chairman of Electric Cloud, Inc. and a professor of computer science at Stanford University. He founded Electric Cloud with John Graham-Cumming. Ousterhout previously was a professor of computer science at University of California, Berkeley where he created the Tcl scripting language and the Tk platform-independent widget toolkit, and proposed the idea of coscheduling. Ousterhout also led the research group that designed the experimental Sprite operating system and the first log-structured file system. Ousterhout is also the original author of the Magic VLSI Computer-aided design program.