Low ratings will end a 72-year run that began on radio.
The daytime show transferred from NBC radio to CBS television in 1952. It has won 69 Daytime Emmy Awards throughout its history.
Guinness World Records has dubbed it the world's longest-running TV drama. More than 15,700 episodes will have been broadcast by the time its final episode airs on September 18.
"Guiding Light has achieved a piece of television history that will never be matched; it has crossed mediums, adapted its stories to decades of social change and woven its way through generations of audiences like no other," said Nancy Tellem, CBS Paramount Network Television Entertainment Group president.