Nick Jr. on CBS and Nick on CBS were the brandings for a Saturday morning children's programming block on CBS that ran from September 16, 2000 to September 9, 2006. The block featured programming from Nickelodeon, which at the time shared common ownership with CBS under Viacom.
The block replaced CBS Kidshow, a block primarily composed of imported Canadian programming, that ran from 1997 to 2000. For the first two years, Nick Jr. on CBS aired programming exclusively from Nick Jr., including interstitials from Face, Nick Jr.'s mascot. On September 14, 2002, Nick Jr. on CBS was rebranded as Nick on CBS, expanding its lineup to include Nickelodeon shows not featured on Nick Jr.'s lineup. The Nickelodeon shows were removed in 2005 in favor for a return to an exclusively-Nick Jr. block. The block's continuity was provided by segments featuring Piper O'Possum.
On December 31, 2005, Viacom was split into two different companies, with CBS Corporation becoming its own standalone company and Nickelodeon going to the new Viacom. Nick Jr. on CBS ended on September 9, 2006 and was replaced by KOL Secret Slumber Party on CBS on September 16, 2006, as part of a multi-year partnership between CBS and Cookie Jar Entertainment.