Ferguson's show airs after "Late Show" with David Letterman, who announced his retirement a few weeks ago. Letterman is being replaced with Stephen Colbert.
Ferguson, 51, told his audience Monday night that he and CBS are not getting divorced, but "consciously uncoupling," which is a reference to Gwyneth Paltrow's much-mocked announcement she was separating from her husband.
CBS Entertainment Chairwoman Nina Tassler said Ferguson "infused the broadcast with tremendous energy, unique comedy, insightful interviews and some of the most heartfelt monologues seen on television."
CBS said it plans to continue "The Late Late Show" and will be searching for another host.
Ferguson, who has been host of the late-night show since 2005, already has a new job lined up. He'll host "Celebrity Name Game," which is a syndicated game show debuting later this year.
The Associated Press contributed to this report.