Doll directs here. For the species of the same name, see Doll (species).
Doll (ドール, Dōru) is a first-string member of the Noah's Ark Circus. She is its tightrope walker, and specializes in aerial ballet. She is considered "the princess" of the Circus with a "death-defying tightrope walk." Doll sometimes adopts the alias Freckles, a second-string member.
Doll is a young female with brown hair, blue eyes, and freckles dotting across her nose. When not performing, she dresses in baggy clothes, which includes a lightweight jacket with two undershirts and brown trousers. The forelocks of her well-nigh shoulder-length hair are sorted so that they conceal her ruined left eye. The eye, though badly scarred and disfigured, is still capable of shedding tears.
When performing, Doll dons a white wig, which appears to be made of white roses, with two feathers sticking out the left side and beads dangling from the side, that ties under her chin in a large bow; it is worn to veil her left eye. There is a design of thorny tendrils painted on her left cheek, that reaches down from her covered left eye. Doll also sports fake white eyelashes, an off-white neckband trimmed in white lace, an off-white strapless dress trimmed with a striped bow and more white roses, off-white sleeves with a poof cap that extends from her shoulder to just below her elbow.
Her footwear consists of off-white ballet-style shoes with a white roses over the toes, a thigh-high, black-and-white striped stocking on her right leg, and a similar white stocking on her left; the stockings are held up lace garters and straps. She sometimes carries a white, fringe-trimmed parasol, which she uses in her performance as a tightrope walker, and occasionally wears light lipstick.
When adopting the persona as a first-string member of the Noah's Ark Circus, Doll appears solemn and taciturn in expression and manner. However, when disguised as Freckles, Doll is cordial, welcoming, and somehow innocent, befriending Ciel Phantomhive shortly after they were named tent mates. She seems to judge it a necessity to look after him, waking him up when he oversleeps, sharing her food when he does not get enough, and teaching him how to be a better performer. Her eagerness to make and be surrounded by new friends is supported by the fact that she often adopts the aforementioned alias because she dislikes sleeping alone and staying with someone else "makes her sleep better sometimes." She is relatively naive, though, and is gullible enough to believe the lies Ciel tells her — she easily forgave Ciel when he claimed he was stealing items — something that the other circus performers reprimanded her for multiple times.
Doll is not modest, as shown when she attempted to get Ciel to take a bath and offered to wash his back for him. She even allowed him to touch her chest — in fact, she had unflinchingly laid his hand there—to prove that she is female, and gave him permission to "take a peek downstairs."
Furthermore, Doll is exceedingly loyal to the other first-string circus performers, and was devastated upon hearing news of Joker's death. She views all of them as family; she calls the other first-string members her brothers and sisters, and Kelvin her "Father."
Doll grew up in an alley in the East End, referred to as a gutter, with the other first-string circus members, minus Snake. Joker stated that they came together because they were each defective in a way. In Doll's case, her left eye is burned and marred, because her parents raised her too harshly and consequently deformed her. As thieves, they were unsuccessful, and they barely managed to survive.
Ten years ago, Doll rushed up to Joker one day with a tooth in her hand. She gleefully exclaimed that it fell out, believing that she would later get a coin from the Tooth Fairy and promised them that she would buy them all bread afterwards.  Unbeknownst to her, Joker, Beast, Dagger, Peter, Wendy and Jumbo worked on manual chores earnestly all night long in order to earn a single coin for her. The next morning, an oblivious Doll showed off her coin to them, stating how happy she was that they could eat bread with it. However, in the belief that the Tooth Fairy would give her more coins, Doll later attempted to take out more teeth that weren't wobbly, to the dismay of the others.
One day, Kelvin found them in the alley and allowed them to come live at his estate, where they lived in relative luxury. Sometime thereafter, they decide to create a circus. Joker gave them all stage names, including Doll, who initially tried to refuse the name, because she believed it does not fit her. Joker dismissed her complaint, saying that of course it did, because she is their "cute little sister."  Her birth name is unknown.
At a circus show that Ciel Phantomhive and Sebastian Michaelis attend, Joker introduces Doll as their tightrope walker. Later, after both Ciel and Sebastian have successfully infiltrated the circus, she is assigned to be Ciel's tent mate as Freckles. She views it as her job to help Ciel out, which she does by waking him when he oversleeps, sharing her food with him when he does not get enough for breakfast, and trying to assist him in improving his coordination for the circus act. After practice, she opts that they go take a bath. There, she forcibly lifts his shirt and discovers his slave mark, before he runs away.
Later, Doll finds Ciel sneaking through the first-string tent, but saves him from being detected by Dagger and Snake. She reveals that she is actually Freckles, and when questioned about her gender, she puts his hand on her chest and offers for him to "take a peek downstairs," which he declines. Ciel claims that he was only planning to steal before he was caught red-handed, as it is a survival habit derived from living in East End, and begs her not to boot him from the camp. Doll forgives him, but admonishes him to not do it again. She states that they are now even, as she has done something terrible to him earlier, referring to when she accidentally saw his slave mark. When Ciel was afflicted with an asthma attack, Doll sleeps next to him on a bed.
Later, after the first-string members realized that Ciel and Sebastian have trespassed their tent then mysteriously left, Doll is physically and verbally reprimanded by Peter for being deceived by Ciel. She asserts that he is merely a child and that they made a promise. Nonetheless, she is distressed that they are unhappy with her, thinking it is her fault that the circus may be in trouble. She is then assigned the task to ride to Kelvin's manor, to inform Joker of the first-string members' intended plan. While on the ride, she sticks by her trust in Ciel, reiterating to herself that she does not believe he is part of the Scotland Yard.
Eventually, Doll arrives at the manor just in time to see it on fire and Ciel and Sebastian leaving the building. She approaches Ciel, deeming that they are still friends, and asks him what is going on. When he slapped her and ordered her not to touch him, she is upset, and demands if everything was a lie. Ciel affirms it so, and he and Sebastian deliver the news that their purpose was to eradicate the circus, and that they have killed Baron Kelvin and Joker. Shocked, she collapses to the ground in tears, and proclaims that she will not forgive them. She draws a knife and attacks them. Ciel calls Sebastian's name, and Sebastian kills her, under Ciel's command.
- (To Ciel Phantomhive) "Blimey. Anyhoo, gimme a shout if there's somethin' you ain't 'ettin'! There's a long life of circus ahead of you!"
- (To Ciel Phantomhive, after he asks why a boy is wearing a girl's costume) "How rude! It's obvious that I'm a girl. Here. You can take a peek downstairs, if you like."
- According to the official Kuroshitsuji's character popularity poll, Doll is the twenty-seventh most popular character in the series, with 25 votes.