As the protagonist and title-character of the novel, Orlando is the primary interest of the narrator. The narrator is a biographer whose duty it is to tell the facts of Orlando's life as clearly and truthfully as possible. Orlando's thoughts and revelations take up a good portion of the pseudo-biography. Orlando's internal life is to be just as active as his/her external one.
Based upon Woolf's real-life love interest, Vita Sackville-West, Orlando shares many of West's qualities: most significantly, a deep reverence for history and family tradition, and a poetic, brooding nature. In her diary, Virginia Woolf wrote that Orlando was meant to be "Vita, only with a change about from one sex to another."
Orlando's sex change mid-way through the novel plays an important part in his character development. While s/he starts out as a young, wealthy nobleman who takes interest in dallying about the royal court with lovely noblewomen, Orlando ends the novel a deep, reflective woman. The change is reflected in Orlando's writing; what was once overly ornate mythological drama turns into a beautiful, mature epic poem. As Orlando ages, and lives through many ages, and realizes that s/he is composed of hundreds of selves and experiences. All of these experiences and selves combine to form the person s/he is at the present moment. S/he is a part of nature, and thus, not immortal; s/he realizes that this self too, will die. Finally, by maturing and by reaching middle-age, Orlando finds that s/he has gained what s/he was looking for: life and a lover.
Sasha is a character who first awakens in Orlando a feeling of despair. Until the point that Sasha deserts him, Orlando has easily had everything he could have wanted. Born into a noble family, and chosen by the Queen at an early age to have great fortune and status, Orlando does not want for anything. But Sasha, an exotic, mysterious princess, changes Orlando's complacency about life. Like all of the other characters, her importance in the novel is measured by the effect she has on the protagonist, Orlando.
Significantly, Sasha awakens in Orlando a deep sexual desire. Even before he knows her gender, he is drawn to her. She moves athletically and wears androgynous clothes; Orlando is attracted to Sasha as an individual, entirely separate from what her gender is at the time. Sasha's exoticism is compounded by her foreign tongue and deceptive manner. Orlando can never be sure exactly what she is thinking, and he feels especially vulnerable when she speaks to the sailor in Russian. As the novel moves forward and Orlando matures, he is better able to understand Sasha and the feminine point of view. Sasha is Orlando's first real experience with love, lust, and female nature.
Sasha's character is thought to be based on Violet Trefusis, a lover of Vita's from 1918–1920.
Like Sasha, Shel is most important in the novel for the effect he has upon Orlando. Shel allows Orlando to conform to the "spirit of the age" by sweeping her off her feet and acting as her husband. Orlando feels lost in the nineteenth century, as if she cannot fit in unless she is attached to a man. While Shel fills this traditional void in Orlando's life by finding her and marrying her as in the Victorian romance novels, he ends up being much more to Orlando than merely a husband. In Shel, Orlando finds someone like her, an individual not defined by his gender. Orlando cannot believe she has found a man who is at once boldly courageous and "as strange and subtle as a woman." Shel combines positive qualities of both genders, and is in fact, compatible with Orlando. Such compatibility is possible because Shel is not a flat, single self. His very name implies the multi-faceted aspect of his personality and his experiences. Orlando chooses to call him "Mar" when she is in a dreamy, amorous mood, "Bonthrop" when she is in a solitary mood, and "Shel" when she is in no mood at all. That Shel challenges all labels and categories, and that he is a complicated person, make him acceptable as Orlando's husband.
Shel is mostly a fantasy character, but some critics have seen resemblances between him and Vita's husband Harold Nicholson, who was likewise openly bisexual. In real life Vita called Harold "Mar" just as Orlando calls her husband the same name.
Based on Henry, Lord Lascelles (1882–1947), one of Vita's suitors, in Orlando, Archduke Harry is a comic character who acts as a foil to Orlando. Though Harry appears to be a perfect match for Orlando (he is also a wealthy nobleman who dresses in clothes of a different gender), their temperaments do not match at all. Orlando's gender change is literal; it occurs almost spontaneously and is fueled by nothing other than chance and truth. In contrast, the "Archduchess Harriet" was created purposefully to deceive. His "gender change" is not a true one; it is a comic one, when the reader remembers that Harry has is over six feet tall and has an extraordinarily long face.
Woolf uses the character of Archduke Harry to parody some of the fictional heroes of eighteenth century romance novels, who likewise do ridiculous things to prove their love. His gift of a jeweled frog to Orlando is accepted with stifled laughter. Although Harry tries to fulfill a traditional role as suitor to Orlando, she cannot bear his boring outlook and slow wit. Harry is a ridiculous figure in both appearance and behavior, and functions as comedic character in the novel.