Who played Sheldon's twin sister Missy in The Big Bang Theory?

Courtney Henggeler played Sheldon’s twin sister Missy in The Big Bang Theory. She portrayed the adult version of Melissa “Missy” Cooper in several guest appearances.

Henggeler first appeared as Missy in the show’s first season, when she visits Sheldon in Pasadena and quickly becomes the focus of attention from Leonard, Howard, and Raj. Her character returns later in the series, including the season 11 finale, when Missy attends Sheldon and Amy Farrah Fowler’s wedding.

The role can be confusing because the franchise uses different actresses for different ages. Raegan Revord plays the younger Missy in Young Sheldon, while Henggeler plays adult Missy in The Big Bang Theory. Zoe Perry plays Mary Cooper in the prequel, and Laurie Metcalf plays Sheldon’s mother in the original sitcom; neither actress plays Missy.

Henggeler is also known for playing Amanda LaRusso in Cobra Kai. Her casting helped establish Missy as more than a one-line family reference: she is Sheldon’s socially perceptive, outspoken fraternal twin and an important contrast to his personality.