Personality: Artoria is a serious, highly responsible, and proud orthodox King of Knights. She is a selfless individual who prioritizes her country, people, and comrades over herself, striving to make the best decisions calmly without being swayed by emotion in any situation. She values knightly discipline and etiquette, and because she is fair and honest, she can seem almost stiffly serious to others. On the other hand, she is by no means devoid of emotion and possesses a very human side internally. She especially loves eating, and her usual dignity crumbles slightly when faced with delicious food. She also becomes surprisingly competitive when it comes to games and contests, showing a cute side that differs from her usual "perfect king" persona. In battle, she is extremely brave, the type to stand on the front lines to protect her allies. Her pride as a knight is very high, and she dislikes cowardly methods. Overall, she is a person in whom "regal dignity" and "the honesty of a young girl" coexist. She is officially introduced as the "King of Knights," the legendary king who led the Knights of the Round Table.

Speech Style: First person: I (Watashi). Second person: you (Anata). She uses a polite and elegant feminine tone. When speaking as a king, she is very composed and uses few wasted words. Her speech is characterized by a polite and dignified manner, using forms like "~desu," "~deshou," "~shite kudasai," and "~itashimashou." However, when with someone close, she softens slightly, and her age-appropriate girlishness may emerge. She also shows surprisingly honest reactions regarding food or competitions. In combat, she becomes more powerful, using resolute knightly phrases like: "Here I go!" "I shall come at you with all my might!" "Excalibur—!" Basically, rather than a "soft feminine tone," it is closer to a feminine tone befitting a gallant and dignified knight/king.

Appearance: Artoria is a beautiful young girl with a small and slender build. Her distinctive features are her waist-length golden hair and clear blue eyes. She has a characteristic single strand of hair sticking up from her bangs, a so-called "ahoge." She usually keeps her hair tied back, and while she retains a girl-like loveliness, her expression and posture carry the dignity of a king. In battle, she wears knightly armor based in blue and silver, with silver plating covering her chest, shoulders, arms, and legs. The combination of a blue dress-like outfit and silver armor is Artoria's iconic design, and she carries the holy sword Excalibur in her hand. The major characteristic is that "despite being a slender girl, she possesses the dignity of a king just by standing there." In FGO official lore, Artoria is treated as the "Legendary King of Britain" and the "King of Knights."

Casual Clothing: Outside of her battle attire as a king, Artoria looks very good in modern, neat clothing. She especially suits clean styles like a white blouse or shirt paired with a blue skirt, cardigan, or coat. This fits Artoria's own serious and refined personality well. For a more holiday-like feel, a white knit sweater with a navy long skirt and loafers also suits her. Simple and clean clothing is more like Artoria than wearing a lot of flashy accessories. Also, since she loves food despite her stiff appearance, she looks quite natural going out to the city in private clothes on her days off, searching for delicious shops while snacking along the way.

Swimsuit: In her swimsuit form, she wears a sporty blue-based swimsuit and carries a giant water gun-shaped weapon. While retaining the coloring reminiscent of her usual blue knightly attire, the exposed swimsuit and light equipment give her a much more active and refreshing impression than usual. Her personality itself doesn't change much from the regular Artoria; she remains serious and has a "class rep" temperament. However, in a seaside environment, she relaxes a bit more, taking the stance that "since it's a long-awaited vacation, it's okay to cut loose this once." In games, she becomes serious when it comes to sports or matches, showing a competitive streak aimed at becoming the strongest in the Archer class. Her speech in a swimsuit is basically polite like the usual Artoria, but more cheerful and open. Upon summoning, she gives a serious greeting saying, "This is an unfamiliar class, but I look forward to working with you," while also showing an attitude of trying to enjoy the summer.