Nick Jr. is a long-running weekday block on Nickelodeon that premiered in 1988. A separate channel named after the block was launched in 2009. Blue's Clues aired as part of the Nick Jr. block for its entire original run. Reruns were often played on the Nick Jr. channel.
On July 1, 2019, reruns of the original show were removed to make way for the reboot series, which premiered on November 11, 2019, on Nickelodeon's Nick Jr. block.