In House M.D., which character is nicknamed Thirteen?

Remy Hadley is the House M.D. character nicknamed Thirteen.

Hadley joins House's diagnostic team during the fourth season and is played by Olivia Wilde. House calls her Thirteen because she is assigned that number during the selection process for his new fellows, and the nickname remains even after her identity becomes known.

The character is a physician with a private personality and a complicated medical history. Her storylines include her bisexuality, her relationship with other doctors, and her hereditary risk of Huntington's disease. These plots give the character both professional and personal stakes beyond the team's diagnostic cases.

Thirteen is often confused with Amber Volakis, who was also part of House's fourth-season fellowship competition. Amber is played by Anne Dudek, while Thirteen is played by Olivia Wilde. The number is a nickname, not Remy Hadley's surname or medical specialty.