The broadcaster hosted Larry King Live daily for 25 years and became one of America's most respected interviewers.
He decided to leave in December 2010, and British journalist Morgan took up his seat to host Piers Morgan Tonight.
King has since hosted several specials for CNN, but he has now left the network once and for all.
A statement from a CNN spokesperson says, "We have the greatest respect for Larry and wish him the best of luck with his new endeavours."