Which character joined House’s diagnostic team under the nickname Thirteen?

Remy Hadley joined House’s diagnostic team under the nickname Thirteen.

Olivia Wilde played Hadley, who became known as Thirteen because she was candidate number 13 during House’s large fellowship selection process. The nickname stuck even after she became a member of the team and later took on other medical roles.

Thirteen is an internal-medicine specialist and is portrayed as a highly capable doctor with a guarded personality. Her story includes a family history of Huntington’s disease, a genetic condition that becomes central to several episodes and to her fears about the future.

The character’s name is often remembered as “Thirteen,” but Remy Hadley is her actual name. She is also distinct from Amber Volakis, another doctor from the same selection storyline, and Martha Masters, who joined the team later. Wilde appeared as a recurring and regular cast member during several seasons.