Halley Wegryn Gross (born December 27, 1985) is an American screenwriter and actress.

She is best known for writing two 2016 episodes of the HBO series Westworld and co-writing the 2020 video game The Last of Us Part II.

[5][6][7] She grew up in New Jersey,[8] including in New Vernon,[9] and attended Pingry School, graduating in 2004.

[8] She attended the Gallatin School of Individualized Study at New York University (NYU) as an undergraduate.

[14] She had her breakthrough as a writer and story editor for two 2016 episodes of the HBO television series Westworld.