X-5 (voiced by Canadian actor Bruce Hunter), is the third member, and robot of Atomic Betty's crew, and is a roughly rectangular headed, bright yellow colored, hovering robot, who takes the role of both the navigator for the Starcruiser and providing any unknown information that they may need for their mission. Due to being a robot, he tends to sometimes spout too much information at inopportune times and is exceptionally pedantic, which usually gets on his fellow crew member Sparky's nerves, and sometimes even Betty's as well. The two of them have a grudgingly respectful working relationship.
Though it is often implied in the TV series that X-5 is an outdated model of Galactic Guardian robot, newer, more advanced model Galactic Guardian robots that have been debuted in episodes, such as X-8.5. in the episode Bye-Bye X-5, have tended to be less reliable.
- Admiral DeGill - commanding officer
- Sparky - alien crewmate
- Betty Barrett - human friend, captain
- Maximus I.Q. - rival
- Minimus P.U. - rival
- B-1 - uncle
- Flavia - girfriend
- Before meeting his "Uncle" B-1 during the events of the first season episode "Battle of the Bots", and the events of the first season, X-5 thought he was a orphan.