Gregor Kiczales is a professor of computer science at the University of British Columbia in Canada. His best-known work is on aspect-oriented programming and the AspectJ extension for Java at Xerox PARC. He has also contributed to the design of the Common Lisp Object System, and is the author of the book The Art of the Metaobject Protocol, along with Jim Des Rivieres and Daniel G. Bobrow.
In 2002, Kiczales co-founded Intentional Software with Charles Simonyi, but no longer has any affiliation with that company.
In 2012, he won the senior Dahl-Nygaard Prize.