Nick Jr.

Since its inception in 1977, Nickelodeon's channel space had aired preschool-oriented programs, including Pinwheel, which was their first original series. These were usually played on weekday mornings, when older children were in school and younger children were not. This block ran from 8:00am to 3:00pm. On January 4, 1988, Nickelodeon debuted a name for its preschool block: Nick Junior. Between September 1988 and mid-1989, the name was shortened to Nick Jr. on-air.[3]

At launch, the block mostly showed imported series purchased from other companies. Eureeka's Castle was the first original series that Nickelodeon made for the block. Brown Johnson, the former vice president of Nick Jr., stated in a 2000 interview that after Eureeka ended production, Nick Jr. became "a neglected daypart" compared to the main Nickelodeon.[4] "Without investment of energy or money, the block floundered until 1994, when the network poured $30 million into a full-scale relaunch," said Johnson.[4]

On September 5, 1994, the Nick Jr. block began its relaunch and introduced an animated host character called Face.[5] Gullah Gullah Island and Allegra's Window, the second and third original series made for Nick Jr., premiered. They resulted in 50% rating gains for the block. From then onward, Nickelodeon continued to create its own productions for Nick Jr. and foreign-made imports were phased out. Blue's Clues and Dora the Explorer became ratings draws for both the block and Nickelodeon as a whole.

Before gaining its own spin-off network, the Nick Jr. block extended to several other networks: Nick Jr. on CBS from 2000 to 2006, and Nick Jr. on Noggin from 2003 to 2009. The Nick Jr. on CBS block ended on September 9, 2006, when CBS replaced its Nick Jr. programming with KOL Secret Slumber Party.[6] Nick Jr. series continued to appear on the Noggin channel until its closure in 2009, when the separate Nick Jr. channel replaced it.

On March 12, 2009, Nickelodeon announced that the Noggin channel would be replaced by a channel named after the Nick Jr. block. The intention was to bring the channel in line with the Nickelodeon brand identity. 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.[7]

On September 28, 2009 at 6:00 a.m. ET, the relaunched Nick Jr. channel debuted, accompanied by the new logo (which was designed by New York City-based creative director/designer Eric Zim). Although the use of an orange "adult" and blue "child" figure was discontinued in the new wordmark logo, the tradition of the "Nick" text being orange (representing the adult) and the "Jr." text remaining in blue (as the child) was retained.[7] As is common with newer networks which have taken another former network's channel slot, some subscription providers have confusingly continued to display the channel's logos as either Noggin, The N, or both as that of Nick Jr.'s current logo on electronic program guides. The Nick Jr. channel played several of Noggin's programs, most notably the interstitial series Moose and Zee, until 2012. It also continued not to accept traditional advertising or marginalize closing credits for promotion of other shows on the channel.

A Spanish language block featuring Nick Jr. and Nickelodeon programs debuted on July 12, 2010 on sister channel Tr3́s. "Tr3́s Jr." aired Spanish dubs of Blue's Clues and Wonder Pets!. The block was ended once the final affiliations for Tr3́s broadcast stations requiring E/I programming expired.

Without warning the viewers on March 1, 2012, an update of Nick Jr.'s image debuted that was produced by Gretel Inc. The Moose and Zee interstitials 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 the voice of a female continuity announcer. Disappointed parents organized a social media effort to bring back the Moose and Zee characters.[8] The channel changed its slogan from "It's Like Preschool On TV" to "The Smart Place To Play" (which was also used as the branding for the Nick Jr. block). In addition, The Upside Down Show, Oswald, Jack's Big Music Show, Franklin, Toot & Puddle, and Miss Spider's Sunny Patch Friends were pulled from the network's lineup; the latter five would return later that year, while the former can still be seen on Nick Jr's website at the time.

The channel's programming at this point began to be hosted by characters from Nick Jr. shows. The channel also began incorporating programming promotions and short features on that date; seven months later, on October 1, 2012, Nick Jr. started airing limited traditional advertising (for companies such as ABCMouse, Kmart, Chuck E Cheese, Nabi, Clorox, Walmart, Lysol and Playskool) in the form of underwriter sponsorships airing in-between shows, whereas its parent network airs longer traditional advertising.

In mid-February 2013, a second Pacific Time Zone-based feed for Nick Jr. was launched, both to allow a unified schedule across nearly all time zones and the reaction of parents to NickMom's scheduling a few months before which meant programming for a mature audience aired in the early evening west of the Rockies.

On September 9, 2015, the social media channels of NickMom announced that the four-hour weeknight block on Nick Jr., along with the NickMom website, would end operations by the end of September 2015 due to Viacom's 2015 cutbacks involving acquired programming and also due to NickMom's low ratings[9] with the time vacated by NickMom returned to traditional Nick Jr. programming. In the early morning of September 28, NickMom ended its 3-year run at 2am ET, with an airing of the film Guarding Tess. No sign off message was shown; after the film Guarding Tess, it faded straight into an episode of Yo Gabba Gabba! at its end. Since then, some of Nick Jr.'s most popular programming, including repeats of Dora the Explorer, Blue's Clues, Team Umizoomi, and Bubble Guppies now fill the four hours vacated by NickMom, whose former website address is now used as a redirect to Nickelodeon's site for parental resources.

Following NickMom's closure, Nick Jr. 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. The "off-the-clock" format was previously adopted by various Viacom networks, such as TV Land, Nick at Nite, MTV, MTV2, and Paramount Network (though in a reversed form, the scheduling format for those channels was designed to add extra advertising loads).

In December 2017, Nickelodeon made a deal with Mattel Creations to move the British show Thomas & Friends to Nick Jr. from its longtime U.S. TV home of PBS Kids starting in 2018.

On May 21, 2018, the network refreshed their imaging with new interstitial pieces and updated curriculum notices, and began to promote themselves as the "Nick Jr. Channel" audibly and visually to avert confusion with the Nickelodeon block.

An HD feed of the channel was launched on August 1, 2013, broadcasting at 1080i60 lines.[10][11] As of 2017, most subscription providers along with DirecTV carry it and downscale it for the standard definition version.

Streaming service Pluto TV, which Viacom acquired in January 2019, added a free version of Nick Jr. on May 1, consisting mainly of older library and archive content.[12]