Tenkai Knights (Japanese: テンカイナイト, Hepburn: Tenkai Naito) is a 2013 Japanese-Canadian mecha anime series based on a toy line by Spin Master, produced by Shogakukan-Shueisha Productions, Spin Master Entertainment and TV Tokyo and animated by Bones. It was directed by Mitsuru Hongo, with Jin Kanada and Hiroshi Ōnogi handling series scripts, Toshihiro Kawamoto and Shigeru Fujita designing the characters, Takayuki Yanase and Fujirō designing the 3DCG characters and MONACA composing the music. The series officially aired on Cartoon Network in the United States on August 24, 2013, and in Canada on Teletoon on September 28, 2013. After a year, it premiered on TV Tokyo and its affiliate stations on April 5, 2014.

In North America, the toys have been on sale since December 2013.

Eons ago, a cube–like peaceful planet named Quarton is populated by the Tenkai, alien robots who could shape–shift into living bricks. Quarton was ravaged by a war between two opposite factions: the Corekai Soldiers, led by the valiant and fearless Commander Beagle ("Beag"); and the Corrupted Army, led by the ruthless Lord Vilius, who desired to obtain the source of Tenkai energy for his own purposes. However, the only ones who were strong enough to defeat him were the 4 Legendary Tenkai Knights of Quarton: Bravenwolf, Tributon, Valorn, and Lydendor. Facing defeat, Vilius unleashed the mighty Tenkai Dragon, who was later defeated by the 4 Knights where its fragments scattered across the planet. These heroes were never seen again. One year later, Lord Vilius and the infamous Corrupted Army have returned, more powerful than ever before.

Now on planet Earth in the year 2034 within Benham City, four young teenage boys, named Guren Nash, Ceylan Jones, Toxsa Dalton, and Chooki Mason, find an interdimensional portal to Quarton where they are chosen by Boreas of the Guardians to become the new generation of Tenkai Knights and prevent Lord Vilius and his Corrupted Army empire from taking control of both worlds.

During the course of the series, the 4 boys learn about teamwork, friendship, and many other life lessons as they face of against Vilius, his 2 henchmen Slyger and Granox, and soon, Dromus (AKA Gen) and Venetta (AKA Beni).

The series first aired in the United States on the cable TV channel Cartoon Network on August 24, 2013, at 7:30 am, and in Canada on Teletoon on September 28, 2013. The English dub is produced by Studiopolis. To coincide with the launch of the property, Spin Master and Kickstart Entertainment produced a 10-episode prequel web-series entitled Tenkai Knights Origins. The series features music by John Majkut and was released onto YouTube as well as the brand's official website between September and December 2013. They also aired as interstitals on Cartoon Network and Teletoon.

In Japan, the television series was delayed until April, airing on the TV Tokyo network beginning April 5, 2014. However, the Saturday 9:00-9:30 slot was a local sales slot, so only TV Aichi and TV Osaka were simultaneously networked with the production station TV Tokyo, while the other three TV Tokyo affiliate stations broadcast it on Saturday mornings at 7:00 (one week later).

A second season of the series was announced to be in development but was cancelled prior to entering production.