Which character joins House M.D. as a fellow using the name Thirteen?

Remy Hadley joins House M.D. as a fellow and becomes known by the nickname Thirteen.

Olivia Wilde played Hadley, who is introduced during the selection process for House’s new diagnostic team. House gives her the nickname Thirteen because she is assigned that number among the applicants, and the name remains associated with her character.

Hadley is an internist whose personal story includes a family history of Huntington’s disease. The possibility that she may inherit the condition becomes a major source of tension and helps explain her guarded personality. Her romantic relationships and professional choices also receive extensive attention.

Thirteen is a nickname, not the character’s legal name. Remy Hadley is the canonical character name, while “Thirteen” is the identifier most often used by House and other doctors. Olivia Wilde remained associated with the role through multiple seasons and later guest appearances.