Toonami (United Kingdom and Ireland)

As programming block on Cartoon Network

In March 2000, Cartoon Network started to introduce anime programming on its schedules, starting with Dragon Ball Z. Batman Beyond (known as Batman of the Future in the UK), premiered on 4 September 2000, being scheduled alongside Dragon Ball Z. This would later become part of a programming block on the channel which eventually became Toonami on 18 December 2000. Throughout its time on Cartoon Network, Toonami introduced more programming including Tenchi Muyo! and Mobile Suit Gundam Wing. Toonami on Cartoon Network would seize broadcasting in June 2002 to make way for a spin-off channel based upon Toonami's high viewership on the channel.

As CNX

On 24 September 2002, Turner Broadcasting System Europe announced that it would launch a new offshoot network named CNX on 14 October. CNX would be the first Cartoon Network derivative to launch outside North America. The channel was initially available on Sky Digital and NTL:home.

Unlike Turner's other children's networks, CNX was classified as a general entertainment network aimed towards a 16-34-year-old male audience. CNX's daytime slot mainly consisted of action shows from Cartoon Network's lineup such as Batman of the Future, X-Men Evolution, Dragon Ball Z and Samurai Jack, alongside a magazine series entitled Trailer Park which featured the latest video games, media, extreme sports content and other media. CNX's nighttime slot mainly consisted of adult-oriented animation (mainly original shows from Adult Swim), martial arts movies, and dramas such as The Shield, Birds of Prey, Sports Illustrated Swimsuit Issue, Space Ghost Coast to Coast and Cowboy Bebop, while films included Point of No Return (1993), and Death Race 2000 (1975).

To promote CNX, six people attempted to break the world record for continuous TV watching, set at 46 hours, 30 minutes, and 50.91 seconds. Three participants—Steven Hayes, Adam King, and Nick Tungett—succeeded, watching for 47 hours. They earned a place in the 2002 Guinness World Records, a £5,000 cash prize, and £2,000 in audio-visual equipment.

Following the channel's launch, Turner was in negotiations with Telewest to add the channel to their Active Digital cable service, and it was soon added on 15 January 2003. In April, Turner Broadcasting System had considered launching a U.S version of CNX, but Mark Lazarus, the former head of Turner Entertainment, stated such a launch was "not imminent", and never materialised.

While the daytime slot was initially branded under the CNX banner, by 2003, it was rebranded under the Toonami name, while the CNX brand remained for the evening. This would soon prove to become the channel's most popular strand.

As Toonami

On 9 July 2003, Turner announced that CNX would close and rebrand as a standalone Toonami channel beginning in September 2003, with a Turner spokesperson citing that the adult market was "crowded and competitive" as the reason for its closure.

On September 1, it was officially revealed that CNX would rebrand as Toonami on September 8, and on that day, CNX closed for the final time at 1 am and its slot on all platforms was moved to the "Kids" sections and relabeled as Toonami, which launched at 6 am on that day.

The new version of Toonami would air much of the same programmes as before, with new additions including Ultimate Muscle and Star Wars: Clone Wars.

TOM returned as the channel's mascot, appearing as TOM 2, and was voiced by Christian Stevenson, otherwise known as DJ BBQ. Stevenson earlier hosted the CNX show Trailer Park alongside Ed Leigh. Previously, when Toonami was still a block on Cartoon Network UK, the block used TOM 1 and had a voice similar to Tansit from Space Ghost Coast to Coast narrating in its bumpers, which many fans believed to be TOM's voice.

In 2005, Toonami was added to the TV and video on demand kids' package for VNL's HomeChoice (now TalkTalk TV). Broadcasting for the channel involved using advanced MPEG-4 AVC compression technology, the first TV channel in the world to do so.

Refocus on Live Action shows

In February 2006, Turner Broadcasting System Europe announced that Toonami would receive a new refreshed look on 6 March and would be restructured as a general entertainment network to broaden its appeal. As such, the channel's slot on Sky Digital was moved to 602 (next to Cartoon Network), and being the first Turner-owned children's network to air live-action shows. The new graphics package would see the stark, simplistic black, white, and red logos replaced with blue, as well as the introduction of giggling, blob-like mascots that populated the channel's bumpers and idents.

Toonami favourites such as The Batman, Pokémon, Justice League, Teen Titans and Static Shock remained in the channel's schedule, mixed-in with new live-action shows such as Backyard Science, Blue Water High, Life with Derek, Parker Lewis Can't Lose and Stencil.

Following the rebranding, Turner announced plans to add live-action programmes to their other channels across the world, with the Latin American version of Boomerang being rebranded similarly as a general entertainment youth network, but unlike Toonami UK, it would be more focused towards a female market.

Merger with Cartoon Network Too

On 2 May 2007, Turner announced that Toonami would cease operations on 24 May and its EPG slot would be taken over by Cartoon Network Too. This was to allow a full-time Cartoonito channel to launch in Cartoon Network Too's original slot on Sky. On May 24, Toonami ceased operations at 3:00 am and Cartoon Network Too moved into the space shortly afterwards. Since its closure, the action animated programming were moved to Cartoon Network Too, as well as few of the live-action programming were moved to Boomerang the following year.