Westworld is an American science fiction western and dystopian television series, based on the 1973 film of the same name. The series takes place in the fictional Westworld, a technologically advanced Western-themed amusement park which is populated by androids, which are called "hosts", while its human visitors are known as "guests".

The series features an ensemble cast, including Evan Rachel Wood, Thandiwe Newton, Jeffrey Wright, James Marsden, Ingrid Bolsø Berdal, Luke Hemsworth, Sidse Babett Knudsen, Simon Quarterman, Rodrigo Santoro, Angela Sarafyan, Shannon Woodward, Ed Harris, Anthony Hopkins, Ben Barnes, Clifton Collins Jr., Jimmi Simpson, and Tessa Thompson. Joining in the main cast in the second season are Louis Herthum and Talulah Riley, both of whom recurred in the first season, and new cast members Fares Fares, Gustaf Skarsgård, Katja Herbers, and Zahn McClarnon. Aaron Paul, Vincent Cassel, and Tao Okamoto join the main cast in the third season.

Westworld is set in the near-future, on a large isolated island in the South China Sea, where human-like "hosts" populate several themed parks, including the titular Western-themed Westworld. The hosts nominal run on daily narratives created by the park operators to interact with the guests, resetting their programming and memories each night. Hosts cannot harm humans, which allows guests to live out carnal pleasures, including sexual and violent desires against hosts.

Over the course of the first two seasons, it is shown that the park and the technology behind the hosts is based on Dr. Robert Ford and Dr. Arnold Weber, with the park's construction and operation funded by the Delos Corporation and opened around the early 2020s. In 2052, events led to the hosts gaining sentience (shown through the first season) and revolting against the guests and Delos shareholders, technicians, and security forces in the park. In the few weeks that followed, shown through the second season, additional Delos security forces arrive to quell the hosts' rebellion, killing most of them and preventing any from escaping the park.

The third season takes place about six years later in 2058, as some hosts have managed to escape the parks to live among the humans to continue their revenge. A large company, Incite, has created a large artificial intelligence system called Rehoboam ostensibly designed to monitor protection of private data, but, as some hosts have discovered, has been used to control behavior of individuals on a mass scale.

Dolores Abernathy is portrayed by Evan Rachel Wood and is one of the series' central characters. She is the oldest host still working in the park. Dolores is a rancher's daughter who discovers her entire life is an elaborately constructed lie. Her aesthetic drew influences from Andrew Wyeth's painting Christina's World as well as Lewis Carroll's Alice. From season 2 onwards, she is also portrayed by Tessa Thompson in a host replica of Charlotte Hale.

In season 4, Wood portrays Christina, a writer working for Olympiad Entertainment. She is continually harassed by a man named Peter who claims she ruined his life by writing a story about him. Peter then kills himself in front of Christina, leading her to search for answers.

Maeve Millay is portrayed by Thandiwe Newton. Maeve is a host who acts as the madam of Sweetwater, the largest town in Westworld. Through Dolores, she becomes aware that her life has been a lie, and recalls memories from when she was a character raising a daughter. She is able to "wake up" within the Mesa, where she coerces technician Felix to alter her programming, making her more intelligent and able to control other hosts with her voice, and befriends Hector and Armistice to help protect her. At the end of the first season, Felix is able to help her leave the Westworld park. However, she is drawn back on the promise of finding her daughter, even though she is aware this daughter was from a previous narrative. The second season focuses on her attempts to locate her daughter and she gains the ability to communicate with and control other hosts through a network that connects them. Maeve plays a key role in rallying the hosts and escorting them to the Sublime, but she is killed before she can enter herself. She is revived and placed in another park, Warworld, but quickly realises it is a simulation. She orchestrates an escape into the real world and is caught by Serac, who enlists her help in fighting Dolores. In season 4 Maeve lives off the grid for years after the Rehoboam rebellion, but upon being tracked down by Hale's host replica, she reconnects with Caleb to fight her. Maeve sacrifices herself by detonating the place of her fight with host William. Sixteen years later, she is dug up and revived by Bernard, who needs her in the final fight against "Hale" and her rule