MACLISP is a dialect of the LISP Programming Language that ran on DEC PDP10 and Honeywell Multics in the 1970’s and early 1980’s.

MACLISP was named for Project MAC, and is unrelated to Apple's Macintosh ("Mac") computer, which it predates by decades. The various Lisp systems for the Macintosh have no particular similarity to Maclisp.