Its lineup features a mix of original programming, along with series from the Nick Jr. block; to avoid confusion between the two different entities, the separate channel has been identified on-air as the "Nick Jr. Channel" since March 2018 to the present day for promos and until September 2023 for the on-screen graphic.

From May 2021 to March 2022, the Nick Jr. channel aired an hour-long block of programming from the Noggin app every Friday.

[6]Since its inception in 1977, Nickelodeon's channel space had aired preschool-oriented programs, including Pinwheel, which was their first original series.

[8] "Without the investment of energy or money, the block floundered until 1994 when the network poured $30 million into a full-scale relaunch," said Johnson.

[8] On September 5, 1994, the Nick Jr. block began its relaunch and introduced Face, its first host and no longer ran commercial breaks as intermissions during shows.

From then onward, Nickelodeon continued to create its own productions for Nick Jr. and foreign-made imports were phased out.

In July of that year, Nickelodeon unveiled new standardized logos for its five channels, intending to create a unified look that could better be conveyed across the services.

[11] Until 2012, the Nick Jr. channel retained Noggin's on-air branding style and played several of its programs, most notably the mascots Moose and Zee.

It also continued not to accept traditional advertising or marginalize closing credits for promotion of other shows on the channel.

On March 1, 2012, the Nick Jr. channel received a new rebrand produced by Gretel Inc. Jessica DiCicco became the network's announcer, and the Moose and Zee mascots were completely dropped after nine years, removing one of the last vestiges of Noggin; as a result, some of the interstitial learning activities that originally featured Moose's narration (like the Puzzle Time segments) were recycled and replaced by her narration.

[12] On September 4, 2023, the channel rebranded to use the refreshed splat logo, as well as new bumpers and curriculum boards (to keep in line with the Nickelodeon block, which began using the new branding on July 5, 2023).

Following NickMom's closure, the Nick Jr. channel increased the amount of traditional advertising it aired, but also began scheduling programs in an inversion of the "off-the-clock" format where the network shortened some of its commercial breaks, allowing the network to air more programming.

As of 2022, the channel's lineup includes The Adventures of Paddington, Baby Shark's Big Show!, Blaze and the Monster Machines, Blue's Clues & You!, Bubble Guppies, Face's Music Party, Hey Duggee, Kiri & Lou, Paw Patrol, Peppa Pig, Ryan's Mystery Playdate, Santiago of the Seas, and Team Umizoomi.

Versions of Nick Jr. also exist in the United Kingdom and Ireland, Germany, The Netherlands & Flanders, India, France, Italy, Latin America, and Australia.