- Beetle Bailey: The title character, Beetle is a lazy, troublemaking soldier who constantly tries to avoid work and find ways to get out of his duties. He is known for his mischievous and often childlike behavior.
- Sarge: Beetle's superior officer, Sergeant Orville P. Snorkel, is a strict, no-nonsense soldier who is often frustrated by Beetle's antics. Sarge is known for his loud voice and short temper, but he also has a soft spot for his men.
- Plato: A fellow soldier and Beetle's best friend, Plato is the more level-headed and responsible of the two. He often tries to keep Beetle out of trouble, but he also gets caught up in his friend's schemes.
- Miss Buxley: The comely secretary to the general, Miss Buxley is a kind-hearted and attractive woman who is often the object of Beetle's affections. Despite his attempts to woo her, she remains unattainable.
- Killer: Camp Swampy's military dog, Killer is a large, ferocious-looking German Shepherd who is actually very friendly and affectionate. He is a bit dim-witted, but he is loyal to Beetle and his friends.
- General Halftrack: The commanding officer of Camp Swampy, General Halftrack is a stern and intimidating figure who is rarely seen. When he does appear, it is usually to issue orders or berate his subordinates.
- Zero: A dim-witted soldier, Zero is known for his low intelligence and cluelessness. He often provides comic relief with his misunderstandings and nonsensical statements.
- Cookie: The camp cook, Cookie is a rotund, jolly man who is passionate about his cooking, but his culinary skills are less than desirable. His dishes often leave much to be desired.
These characters, along with a rotating cast of supporting characters, make up the comedic ensemble of Beetle Bailey, providing readers with laughter and entertainment through their interactions and antics.