The show is set in the year 100,000,000 AD, on a satellite which orbits Earth. This future Earth is never visited directly, though it is referred in dialogue as a peaceful utopia where there are no longer any problems to solve. All nations of the world have merged into one, and, according to Tuddrussel, there are "no wars, no pollution, and bacon is good for your heart."
Despite this cheerful vision of the future, the space station on which the characters live and from which they travel to the past is remarkably dystopic. It features a shooting range, a terrarium, and a prison for repeat offenders, but it is dank, outdated (for the time) and unclean. Mostly this seems to be down to Officer Buck Tuddrussel, a scruffy and immature perennial bachelor, who nevertheless happens to be the station's most senior officer. There were also several accidents aboard the Time Squad Space Station; most notable of which is the terrarium being broken after Tuddrussel plays golf and breaks the glass shell of the station. This action seems to have no consequences in future episodes.
The only other official member of Buck's unit is Larry 3000, a translator robot and former diplomat who was rendered more or less obsolete when all of the world's nations merged. Buck's mindless machismo clashes with Larry's effete sensibilities, and the two bicker terribly. Added to this the fact that neither of them has any great knowledge of history, they made a rather poor team together.
However, when they encounter Otto Osworth, an eight-year-old orphan who happens to be a history genius from the 21st century, he is quickly recruited and added to the team. Otto is shown to be the only one on the team with any enthusiasm or competence for the job. The problem is, neither of the other two are particularly willing to listen to his advice, and he must often resort to trickery to make sure the mission is completed.
Otto Osworth (voiced by Pamela Adlon): An orphan illegally traveling along with Tuddrussel and Larry, taken on board due to their incompetence and his impressive historical knowledge (and for Otto to escape his brutal life at the orphanage). Despite being a bookworm, his demeanor is far from boring; he is just as childlike and jocular as any regular 8-year-old. Even though he is the youngest, he is also the most responsible out of the squad, being the only one pure enough to not let himself get swayed by temptations. Depending on who he's siding with, he can either become loud, obnoxious and destructive (when Tuddrussel has him company) or composed and calm (when it's Larry he agrees with).
The Lawrence "Larry" 3000 (voiced by Mark Hamill): The resident Robot Buddy and the only one on board able to operate the computer. It's his job to make sure the squad ends up at the right time and place. Initially, he was programmed as a polyglotic robot for diplomatic purposes; when all of the nations rejoiced into one, huge country, his consular abilities were no longer needed. Larry is famous for his effeminate behaviour and interests, which are portrayed all but subtly. Unusually, he is extremely dramatic and open in showing his emotions whilst still being the snarkiest of the trio. He prides himself in having knowledge of proper etiquette and manners. For Otto, he has been repeatedly depicted as a maternal figure.
Officer Beauregard "Buck" Tuddrussel (voiced by Rob Paulsen): A time cop, who possesses all the physical requirements for his job and none the intellectual. Whenever there's someone who needs a beating up (and even when they don't), he's the best person to get assigned for such a task. Impulsiveness, aggressiveness and air-headedness are traits which define Tuddrussel quite nicely. Not much of his backstory is known, aside from his Southern heritage and a short-lived marriage to fellow time cop Sheila Sternwell. He and Larry have a typical Vitriolic Best Buds relationship (which can legitimately be read and proven as Belligerent Sexual Tension by some viewers), and he is much like an irresponsible father to Otto.
Sheila Sternwell (voiced by Mari Weiss): A lieutenant within Time Squad ranks, Sheila Sternwell is a no-nonsense woman that takes her job seriously. The ex-wife of Buck Tuddrussel, it's made clear that while she regrets making the mistake of marrying in the first place, and can be slightly bitter towards him, she doesn't actually resent him and still does her job and helps out Tuddrussel and his unit when needed. She even seems to go far in not ratting out Tuddrussel and Larry over Otto, and other screw ups that she should be reporting.
XJ5 (voiced by Daran Norris): A advanced robot that is more qualified for the job of a time cop than Larry, and he loves to rub it in. Working with Officer Sternwell, he provides actual help and guidance on missions.
J.T. Laser (voiced by Jim Wise): Professional and competent, he's the best of the best of what Time Squad has to offer; but he's also a arrogant jerk that gladly makes trouble for Tuddrussel and Larry.
Lance Nine Trillion (voiced by Kevin Michael Richardson): The best officer in Time Squad needs to have the robot with the most advanced technology right? Lance is the perfect partner for J.T.
Sister Thornley (voiced by Dee Dee Rescher): Otto's former caretaker before getting taken by Larry and Tuddrussel. Otto had good reason to fear her, as did the other kids that she kept. Obviously not afraid of the police or anyone coming after her, Sister Thornley freely abuses the kids that are put into her care, while at the home and even more disturbingly in public. Her motives are despairingly questionable, such making the children work under horrific conditions in order to make a quick buck. Or why she had a problem with Otto reading books. (Or any child reading, for that matter. She apparently had an entire policy against it.) Quick to punish, she makes it clear that one does not want to cross her path.