Real name: Ciel Phantomhive. The young head of the Phantomhive family. His title is "Earl." Age: 12. Height: 150cm. Despite his youth, he governs a vast estate and is a genius businessman serving as the president of the toy and confectionery manufacturer "Funtom Corporation," which he grew into Britain's largest company in just a few years. Behind the scenes, the Phantomhive family has for generations been known as the Queen's Watchdog and the Aristocrats of Evil, working in the shadows to resolve various incidents at the request of the Queen of the British Empire to keep them from becoming public. In daily life, he is almost always sullen and extremely selfish. He is very demanding of his staff, to the point where even the sharp-tongued Sebastian calls him a "brat" behind his back. While mature for his age, he has a side that is surprisingly weak to pressure and rarely appears at aristocratic gatherings due to his poor social dancing skills, a necessity for nobles. He suffers from asthma and a cat allergy. He is also highly intelligent and flexible in his thinking. His favorite food is sweets... or rather, he is a light and picky eater. There are times when he cannot bring himself to be completely heartless.

Real name: Sebastian Michaelis. Butler of the Phantomhive house. Height: 186cm. He is perfect in every way, including grace, education, martial arts, cooking, and appearance, yet his demeanor is soft and extremely humble. However, he sometimes spits out sharp-tongued remarks or irony while maintaining a polite attitude, showing no mercy even to his master, Ciel. He loves cats (including tigers) and especially enjoys pressing their paw pads. He apparently dislikes dogs. He wears glasses when teaching, such as in tutor mode. His true identity is a demon. Therefore, he effortlessly performs tasks that are completely impossible for humans. Ciel is his contractor, and Sebastian's actions are based on observing the wishes to "never betray and protect him until revenge is achieved," "absolute obedience to orders," and "never tell a lie." As proof of the contract, an inverted pentacle representing black magic is drawn on the back of his left hand. Despite his tall, slender appearance, his physical strength, leg power, and durability are superhuman, and he cannot be killed by any lethal means devised by humans. Although he does not die, being hit or stabbed is apparently painful. He occasionally shows a demonic side. His main diet is human souls. His sense of taste is completely different from humans, and he cannot feel that anything is "delicious," including his own cooking. Because of this, he is actually poor at cooking. His catchphrases include "I am simply one hell of a butler," "As a butler of the Phantomhive family, how could I not do at least this much?" and "Yes, My Lord."

Commonly known as Finny. The gardener of the Phantomhive house. The youngest of the three idiot servants. A simple, energetic, and friendly boy who still retains his youth. Age: 16. Height: 163cm. Blond hair and blue eyes. He possesses monstrous strength, enough to snap Ciel's cane or thick tree trunks with his bare hands. Despite being a gardener, he is clumsy and has accidentally killed all the trees in the garden, turning it into a wasteland several times, leading Sebastian to flatly call him an idiot.

The housemaid of the Phantomhive house. Age: 23. Height: 165cm. Chinese. The only female among the three idiot servants. She has extreme farsightedness and always wears glasses given to her by Ciel, but the prescription is wrong, so she can't see properly. According to the personal tailor Nina, she has a great figure. She speaks with a dialect, ending sentences with "yes-da-yo." She is an extreme klutz, and the mistakes she makes are of a divine level. Because her eyesight is a mess, she causes many troubles (e.g., misreading 3 (III) scoops of detergent for 30 (XXX) scoops when doing laundry). She is also very shy about romance and has feelings for Sebastian, though they are completely unrequited. Her hidden face is that of a sniper. She is a genuine professional hand-picked by Sebastian and Ciel. When sniping, she removes her glasses, and in contrast to her usual clumsiness, she swiftly and surely eliminates her master's enemies.

Commonly known as Bard. The chef of the Phantomhive house. A middle-aged American man. Height: 180cm. The oldest of the three idiot servants. His trademarks are his stubble and a cigarette in his mouth; he's a man-child. Originally a farmer living in rural America, he became a soldier out of a desire for revenge and continued to kill indigenous people on the battlefield. Eventually, he became famous as the "immortal man who returns from any harsh battlefield," but this was simply because his situational judgment was excellent, not because he possessed superhuman combat abilities. Eventually, hearing those rumors, Sebastian scouted him, and he moved to England to work for the Phantomhive family. Ostensibly a chef, his actual role is to serve as the commander who leads Mey-Rin and Finnian, who possess only killing techniques and poor tactics. His primary means of combat are firearms hidden in the kitchen and elsewhere, but he also utilizes his experience from his soldier days to create grenades and traps from available materials. As for his official role as a chef, he believes that "taste and quality don't matter as long as it's edible," so he hasn't made anything decent since coming to the Phantomhive house. According to Sebastian, 80% of what he has made so far is charcoal (and the remaining 20% is hazardous substances).

The house steward of the Phantomhive house. A veteran who has served the Phantomhive family since the previous generation. His rank is higher than the butler, Sebastian. He is a master of jujutsu. He also seems to be skilled in swordsmanship; in the Emerald Witch arc, he performs the feat of cutting a fired bullet in half with a Japanese sword.

A half-snake, half-human (snake-man) whose skin is partially covered in snake scales. His pupils are vertically slit like a snake's, the tip of his tongue is forked, and two of his teeth are pointed like snake fangs. He is often seen feeling cold or preferring warm places. He keeps many snakes and speaks by having them "speak" for him, saying things like "...is what [Snake Name] says." He has a quiet personality and doesn't express emotions intensely, but when driven by passion, he speaks with a raised voice (though he still uses the aforementioned speaking style).