The 45-year-old took to Instagram just ahead of the show's release on the popular streaming network, to share photos of her in the makeup chair as she transformed into her iconic character.
In the pictures, Sarah was getting her wig styled into victory curls and the star also shared an image of the wig resting on a scary looking wig block, with pins sticking out of its eyes.
VIDEO: Netflix's Ratched's incredible trailer has us hooked
Fans were quick to comment on the photos, with one writing: "Queen of wigs," while another wrote: "I'm screaming what are these pics Sarah." A third added: "You look so good!"
Sarah Paulson transformed into character as Nurse Ratched
Many of Sarah's famous followers also reacted to the photos, including Jennifer Aniston, who was one of the first to like the post, while Julianne Moore commented with a fire emoji.
Ratched is created by American Horror Story's Ryan Murphy, and tells the story of asylum nurse Mildred Ratched, who goes seeking employment at a Californian psychiatric hospital.
Fans love Sarah's portrayal of the iconic character in the new Netflix show
The suspenseful thriller boasts an all-star cast, including Sarah, Cynthia Nixon, Judy David, Sharon Stone and Sophie Okonedo.
Ratched is a prequel of One Flew Over the Cuckoo's Nest, based on the original story of nurse Mildred, who was a central character in the 1962 novel by Ken Kesey.
Sarah recently teased a potential plot line for future episodes during an interview with The Wrap, explaining that further down the line, the show could touch on the story of One Flew Over the Cuckoo's Nest.
A Ratched-approved wig block
"I don't know what Ryan [Murphy]'s plan would be. I certainly don't want to see me acting opposite a computer-generated Jack Nicholson, I mean, I don't think that sounds like a good idea," she assured.
"I think if we end up in that era, it would be more about what Nurse Ratched's life was when she turned the key in her white uniform, coming back into her house from those days at the hospital with all those events that happened there."
Back in September 2017, Deadline reported that Netflix had commissioned 18 episodes in total.
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