Annie Hamilton is not the child of anyone famous. She’s not a profitable influencer, self-made YouTuber, or an overnight TikTok celebrity. Still, Ms. Hamilton has become something of a cult figure for a young generation of actors and people who love talented messes. On Twitter, Instagram and Substack, the 29-year-old New Yorker has been creating a mesmerizing, mirthful, at times harrowing, narrative of her bicoastal life.

She posts self-taped auditions for roles she failed to get; glamour shots paired with photos of her shoe-mangled feet; and tales of rejection and loneliness and cigarettes. Ms. Hamilton can feel like a throwback to one of Warhol’s Factory Girls, balanced between self-importance and self-destruction in a Manhattan of yellow cabs, pay phones, tabloid crime and a rumored portal to dreams coming true.

“I had known about Annie Hamilton as a Twitter personality,” said former Interview editor Nick Haramis. “She fascinated me from afar. Then I was at a birthday party in New York and Annie emerged from the fire escape, having had a cigarette. I screamed ‘Annie Hamilton!’ I was like, ‘I don’t care what else is happening at this party, I want to spend the night talking to Annie.’”

In one 60-second Instagram video, Ms. Hamilton, wearing a dark blue T-shirt and jeans, kneels outdoors on a sunny brick patio in Los Angeles, looking into the camera: “I feel…really sad. I’m stuck here, I’m stuck in like this sunny hell.” Before the viewer can process what they are seeing, Ms. Hamilton’s tear-streaked face announces, “Wait I’m gonna pee.” Seconds later, as urine pools between her feet on the bricks, Ms. Hamilton sobs: “It’s not that I owed it to you all to show how I feel, it’s that I am a miserable person, who wants to show everyone how I feel because I don’t know what else to do with my feelings.”

It’s shocking, endearing and impossible to categorize. Part of the draw of Ms. Hamilton’s social media is trying to sort out where the stress falls in the shadowland between fact and fiction. What is an audition, and what is real?

“It’s all an act, but it’s not a lie,” said Ms. Hamilton’s friend Dasha Nekrasova, who plays Comfrey on the HBO series “Succession.”

On a cold, sunny afternoon in November, Ms. Hamilton stood smoking Parliaments and drinking black coffee outside Cafe Gitane on Mott Street in Manhattan’s Lower East Side neighborhood.

“I don’t like just acting for the camera,” Ms. Hamilton said. “I like acting in real life, too. I like putting myself in situations. It gets me into a lot of trouble.”

She was dressed in a red Sonia Rykiel sweater she bought from The Real Real, a blue-and-white striped shirt, her grandfather’s leather bomber jacket from World War II, Levi’s vintage, dark wash bluejeans and red Hogan sneakers.

She was in a bright mood: A few weeks earlier she’d done standup at The Jane Hotel, for a mixed-age crowd. (“At 11 years old, I lied about the worst thing a person could lie about,” she told the sold-out room. “I lied that my Nana was a Holocaust survivor. My to-be best friend had a Nana who was a real Holocaust survivor, and I really wanted to bond up.”) The show was a hit, and The Jane has booked her for a monthly showcase, starting January 25.

“A year or two ago, I became aware that I had made sort of a character online,” said Ms. Hamilton. “And now I play into that. If I recognize that I could do something crazy or kooky or wild or sensationalist, I will do it and then put it online. But I don’t view any of it as particularly honest. What I’m willing to tell people is all smoke and mirrors. I might flaunt a disgusting habit or story about myself, but really that is to conceal what truly is disgusting.”

Her friend Lorraine Nicholson, a Los Angeles-based screenwriter and director, said, “The thing that’s so attractive about Annie to women is that what she’s doing and saying publicly is what so many of us feel privately.”

After living in Los Angeles as an actor for nine years and working odd jobs such as karaoke hostessing, nannying, and canning and labeling organic body oils in a garage in Beverly Hills, Ms. Hamilton moved back to New York City last year. She lives in a sporadically heated studio apartment for $1,000 a month near Dimes Square, five miles south of NewYork-Presbyterian/Weill Cornell hospital where she was born. Ms. Hamilton’s mother is a stylish, intellectual, Jewish, Upper West Side mom. She dressed in all-black Agnés B. and doted on Ms. Hamilton and her brother, introducing them to writers like Sylvia Plath and Allen Ginsberg and plays like “The Glass Menagerie” and “Through a Glass Darkly.”

“I would come home from a play date and the first thing my mom would say is, ‘How many books do they have?’” said Ms. Hamilton. “And if I liked the kid and they didn’t have many books, I’d say, ‘They have a lot of books,’ because otherwise I wouldn’t be allowed to go back there.”

Ms. Hamilton said her father spent most of his time away from home working on real estate deals in Rapid City, S.D., where he lived in a 6,000-square-foot, Frank Lloyd Wright-style house with an indoor pool. He drove two Ferrari’s and considered himself something of a wild man. He grew a mustache that swooshed up at the ends. The family started spending summers there.

“I felt very lonely,” said Ms. Hamilton. “I really wanted to be Catholic. The cool girl at the country club was Catholic and I went to a Catholic summer camp, where I took an unwarranted First Communion and got in trouble for it. Everyone was going up to take a cracker, so I took one.” Her parents split up when Ms. Hamilton was 15; she didn’t speak to her father for years; her mother still lives on the Upper West Side.

Ms. Hamilton and her mother text seventeen times a day. “I’m not sure how I feel about that but I can’t quit her and she can’t quit me,” she said.

Ms. Hamilton wanted to be a ballerina, and when she was 11 she was accepted to the Alvin Ailey school of dance. “I had a teacher named Miss Howard — who called me — my real name’s Antonia — and she coined the term that I was Tornado Toni,” said Ms. Hamilton. “I was good at jumping and good at spinning and I would throw my body around pretty violently.”

For her high school yearbook, at the Ethical Culture Fieldston School, Ms. Hamilton chose a quote from the actor Zoë Tamerlis Lund, who’d been director Abel Ferrara’s muse and collaborator on the 1992 movie, “Bad Lieutenant.” According to Ms. Hamilton, Fieldston didn’t approve of the choice, “because Zoë was a raging heroin addict.” But the line (“That which is not yet, but ought to be, is more real than that which merely is”) captured something Ms. Hamilton still feels. “My dreams are more real to me than my life right now,” she said.

Ms. Hamilton attended U.S.C.’s highly competitive BFA program in theater. Her first year out of U.S.C., she booked several small acting jobs, including “Dance Camp,” a YouTube Red movie, directed by Bert & Bertie, also known as Amber Templemore-Finlayson and Katie Ellwood. They also recently cast Ms. Hamilton opposite Florence Pugh in an upcoming episode of the Marvel series “Hawkeye.”

“There’s something about Annie that’s not of our time, like she is out of joint with the current culture in a really special way,” said the artist Aria Dean, who directed Ms. Hamilton in a play in Geneva, Switzerland.

“She’s like this 1940s kind of archetypal Hollywood broad, fire-crackery and fast-talking, with her sort of clipped speech, a quick-wittedness and brazenness that you don’t see onscreen these days. The one who’s like, ‘I’m not going to shut up, but I’m still onscreen to get the guy.’”

Aside from “Hawkeye,” Ms. Hamilton has minor roles in Shonda Rhimes’s upcoming Netflix series, “Inventing Anna,” in which she plays a movie star, and a scene with Diane Keaton in Kate Aselton’s comedy, “Mack & Rita.”

“Annie is one of the actors who can do more than one thing,” said Cassandra Kulukundis, Paul Thomas Anderson’s casting director on films such as “Magnolia,” “There Will Be Blood” and “Phantom Thread.”

“You can see her coming and think she’s one thing — and then you’ll realize she’s completely another. Those are the surprises that keep audiences coming back, when they don’t know if you’re going left or right.”

Lately, Ms. Hamilton has been spending time in her Chinatown apartment, wearing three pairs of socks, writing her upcoming Jane show and continuing to perform for her followers on Instagram.

Over coffee, she described a fantasy she used to calm herself while driving down the freeway in Los Angeles. In it, she was interviewing someone to be her personal assistant. “I would say, ‘I know I can be a lot. I know I have a temper. And I’m extremely vain. And I’m always applying makeup, and I cry when I can’t get the right outfit. And I’m a total terrorist emotionally and you’re going to have to deal with all this stuff.’”

That vision evolved into another car fantasy where she was on the David Letterman show. Men would call in and claim they had sex with her and all of their claims would be true. “Everyone would expect me to deny these claims, but instead I would sit and be held accountable for my torrid and wild sexual past. And instead of being the actress that they want me to be, I’d be some sort of truth sayer.”

Whether it’s true or not, Ms. Hamilton knows it’s compelling.

“Ultimately stories are stories — what does it matter if they’re real or not?” said Odessa Young, her friend and actress who appeared in the film “Shirley” opposite Elisabeth Moss. “Annie has been lied to her whole life. She’s a young woman — of course she’s been lied to her whole life. Annie is saying, ‘Oh, you want to make me a story? I’ll give you a story.”