Admiral DeGill (voiced by British-born Canadian Television and Film actor Adrian Truss) is not only commanding officer of the Galactic Guardians but he is also Atomic Betty's immediate superior, and assigns both her and her team to their various galactic missions. He greatly resembles a regular sized anthropomorphic orange goldfish dressed in a blue military uniform with a crew cut of grey and white hair (formerly blonde), and a muscular physique. He also speaks with a slight British accent and usually favours a corncob pipe that blows bubbles. Admiral DeGill radiates professionalism and takes his role as a Galactic Guardian commander very seriously, but has nevertheless managed to strike a balance between both his commander duties and his recreational pursuits.
Admiral DeGill is revealed, in the two part Season 2 finale epsiode Takes One to Know One, to be one of the original founding members of the Galactic Guardians, and is often accompanied by three human sized attractive looking female fish escorts, known collectively as the Rockettes.
Although there have been very few glances into Admiral DeGill's personal life outside the Galactic Guardians, he has an identical twin brother named Tex DeGill, who is sheriff on the western styled water planet of Ainrofilac Ubilam, and his teenage daughter, and Admiral DeGill's niece, named Lilly Rose, who is also Tex DeGill's deputy; he also has a sister, who has a son, his beverly hills surfer nephew, Commander Lamphray. Pontifidora the Conquistadora was once DeGill's girlfriend and fiancée. Her vendetta against Admiral DeGill is mainly due to how their relationship ended (DeGill ran off with a show-girl from the planet Vega). Pontifadora apparently turned to a life of crime after DeGill left her, which led to him capturing her and having her sent to Durango Maximum Security Prison.
- Admiral DeGill's name may be a reference to Admiral Gerard DuGalle, a UED Admiral from the computer video game Starcraft, due to the switching of DuGalle into DeGill.
- Admiral DeGill's name may also be a reference to General de Gaulle a famous French Officer in World War 2.