Ophelia, a name sometimes written as Orphelia, is a mysterious woman in the anime Romeo × Juliet who serves as the guardian and caretaker of the Great Tree Escalus, the sacred tree that sustains the floating city of Neo Verona. She is ageless, looking exactly the same more than fourteen years before the story begins as she does during its events. Her appearance is striking: a sad, doll-like face with markings on her forehead and cheeks, and a polite, enigmatic way of speaking that keeps her intentions hidden. Beneath her robes, her limbs and skin are wood-like, revealing that she is not an ordinary human but a living part of the tree she tends.

Her personality is quiet, patient, and outwardly gentle, yet defined by complete single-mindedness. Her entire existence revolves around the Great Tree Escalus, and she treats its survival as a purpose above all else. She remains calm even while carrying out terrible acts and shows no hesitation once she decides on a course of action. Her motivations are bound to the tree's condition: Escalus is fading, and Ophelia believes its will must be fulfilled to save Neo Verona. Late in the series, she explains that the tree has implanted its seed inside Juliet and that Juliet must be offered in a sacrificial rite so the tree can be revived. Ophelia pursues this goal with little concern for interruptions, alternatives, or the human cost involved.

Her role in the story shifts gradually from mysterious bystander to true antagonist. Early on, she appears as a strange but seemingly benevolent figure caring for the tree. When Juliet is captured by Montague's forces and manages to escape, she encounters Ophelia, who gives her the means to save Neo Verona by planting the tree's seed within her, though this gift carries the hidden price of Juliet's own life. For much of the series, Ophelia remains an unreadable presence in the background. Near the climax, her real purpose comes to light: she seizes Juliet and forcibly begins the sacrificial rites, determined to complete the ritual no matter who stands in her way. This places her as the final obstacle to the protagonists and directly sets up the tragedy that closes the story.

Her key relationships are shaped by her devotion to the tree. Her bond with Escalus is the center of her being; she acts as its voice and agent and is physically connected to it. Her relationship with Juliet changes over the course of the series, moving from mysterious benefactor to captor, since she regards Juliet as a chosen vessel rather than as a person. This brings her into conflict with Romeo, who fights to protect Juliet. In their final confrontation, Ophelia manages to mortally wound Romeo before she herself is vanquished, and the injury she deals him cannot be undone, sealing the fate of the two lovers.

In terms of abilities, Ophelia is far more formidable than her delicate appearance suggests. She is ageless and possesses a body partially composed of wood, giving her an inhuman, supernatural nature. She can channel the power of Escalus, implant the tree's seed within a human being, and conduct the ritual intended to restore the tree's strength. Despite her frail look, she is able to fight Romeo, an accomplished swordsman, and strike him a fatal blow, indicating considerable physical capability. Her name is drawn from the character Ophelia in Shakespeare's Hamlet, following the series' broader habit of borrowing names from other Shakespeare plays, and it suits the tragic role she plays in the narrative.