Benjamin Kirby "Future Ben" Tennyson is the future version of Super Ben.
Future Ben is shown to be mindful of Paradox's wishes to keep his identity secret, though this is only done because he wishes to be the future for the present Ben. As of the events of The Sea's the Limit, the events occurring for the present Ben also unraveled for him, so he remains the most likely future for Ben.
He keeps his identity a secret, being referred to as "Future Ben." It is unknown whether he is built like the previous Ben 10,000's, that he's more like the present Ben, or another option.
He prefers XLR8 as his go-to alien when it comes to getting around.
Despite having aliens that overpower some of his classic aliens (such as Heatblast, Cannonbolt, Goop, and Clockwork), he still uses the classics for the nostalgia it brings.
He is aware that Elena Validus has a crush on him, even at his current age. He plots with Elena (who also works with Albedo, Scarogus, and Tersce Tenebrosi) to keep the secret that she has Magister Frikton in a jail cell on the Commander's ship from his present self, but his motives are not clear.
- In The Sea's the Limit, he appeared using an array of aliens, including Atomhammer, to stop Overlord Zyzz and Murmadan by sending them to the Vigilanuum home world of Chronospect, a time-defiant jail which exists beyond every timeline, as well as in every timeline, as one. He also begins the Plumber initiation process for a Gourmand named Gooron.
- In Happily Never Happened, he is mentioned several times by Ilario and Kitty Rhymes, and later appears during Endgame as Thep Khufan Commander Tersce Tenebrosi watches over Chronospect.
- In Revelation, he appears to thwart Vilgax, Malevolence, Slix, and Cyanne Albedo to ensure. Future Ben lets Cyanne go as his freedom is crucial to the occurrence of events in Future Ben's past that lead to his present.
- In Ledger Recon, he breaks the news to Super Ben about Gwen's and Chelsey's deaths.
- In Welcome to Chronospect, he joins Super Ben in Chronospect in an attempt to stop the Thep Khufan Commander before he attains the Chronogen crystal—the last piece of the Tritadagen. The attempt ends with him being murdered by the Commander so as to reattain the Chronogen and make it back to the Tertiary Wing safely. When he is killed, the Commander takes his Omnitrix and kicks him off the edge of a rock on the planet, dropping him into an abyss.
Back in Action: Alien Universe
- The Sea's the Limit (first appearance)
- Happily Never Happened
- Ledger Recon
- Welcome to Chronospect (killed)
- Ben 10: Alien Universe Unleashed (revived; Endgame only)
- Fate of the Helpers
- Never Set in Stone (confirmed)
- Alien X (fully controlled)
- Alkamine (possibly, mentioned in Ten Plus Twenty)
- Bugbite (confirmed through a picture)
- Muckslide (possibly, younger self used in Unity Broker)
- Autosassin (possibly, younger self used in Welcome to Chronospect)
- Ultimate Upchuck (possibly, younger self used in Welcome to Chronospect)
- Abstallion (possibly, younger self used in Ben 10: Alien Universe Unleashed)