Katy O'Brian is an American actor, writer, and martial artist. She was born in Indianapolis, Indiana on February 12, 1989. At the age of 9, O'Brian earned her brown belt in Shorei Goju Ryu Karate. She attended Indiana University Bloomington, majoring in psychology and Germanic studies. She was one of the first members of the university's short-form improv troupe Hoosonfirst and received law enforcement certification through the university's Cadet Officer Program. While at the university, she received her black belt in Hapkido through the United States Hapkido Federation. After graduation, O'Brian was a police officer at the Carmel Police Department in Carmel, Indiana. While working for the department, she obtained her personal trainer certification and began competing in bodybuilding figure competitions. She also began her training at the Indy Actor's Academy.
O'Brian's first television role was on Comedy Central's Tosh.0 in 2017, quickly followed by other co-starring roles on AMC's Halt and Catch Fire, AMC's The Walking Dead, and ABC's How to Get Away with Murder.
In 2018, O'Brian booked her first regular role on Syfy's zombie series Z Nation where she played George, a budding leader of the apocalypse. In 2019, O'Brian appeared on The CW's superhero series Black Lightning as an ASA antagonist, Major Sarah Grey. She has since appeared on HBO's Westworld, and as Kimball in Marvel's Agents of S.H.I.E.L.D. on ABC.
O'Brian is also known for her roles as Jentorra in Marvel Studios' superhero film Ant-Man and the Wasp: Quantumania, and as Imperial communications officer Elia Kane in the second and third seasons of The Mandalorian on Disney+.
She is married to Kylie Chi and the couple live together in Los Angeles, California.