Benjamin Kirby Tennyson is the titular main protagonist of the Ben 10 franchise. He started out as a normal 10 year-old human boy, before he discovered the Omni Matrix or Omnitrix for short, an alien device which grants him to power to temporarily transform into a variety of alien creatures, each having their own set of superpowers and abilities.

Ben's Omnitrix is said to contain the DNA of at least 1,000,912 aliens combinations with at least 70 unlocked by Ben.

There are several different versions of Ben. His classic versions which consist of his 10 year old form from the original series, his 15 year old form from Ben 10: Alien Force/Ultimate Alien, and his 16 year old design from Ben 10: Omniverse. He also has his adult form, known as Ben 10,000. Finally, there is his new form from the Ben 10 reboot series.

When tagging this tag should be used in posts where Ben appears in any of his normal human forms or partially transformed. If he appears as any of his alien forms such as Wildmutt, Heatblast, or Four Arms; then the posts should be tagged with the alien character names instead. Additionally, not every alien from the series is one of Ben's Alien forms. They should be tagged only if the Omnitrix or some other factor is present to indicate it is one of Ben's forms.