Once upon a time at the Smith house

Among the keepsakes and stacks of books throughout Harley Quinn Smith’s bedroom, don’t look for any volumes by tidiness trainer Marie Kondo — the compulsion to collect is a family tradition.

“I’m obviously not a minimalist,” said Smith, 20, an actress and musician who appears in Quentin Tarantino’s “Once Upon a Time … in Hollywood.” “I have stuff I’ve kept my whole life. There are things in here I refuse to let go of.”

Named after DC Comics hellion Harley Quinn by her parents, filmmaker Kevin Smith and actress Jennifer Schwalbach Smith, she has decked out her bedroom with tributes to the character, including posters and animation cels.

“I guess I had this path laid out for me,” Smith said. “I’ve always loved comics. I was destined to be a nerd and I can’t not accept my name and where it comes from.”

Smith’s affinity with comics, theme parks and movies has informed the aesthetic of her bedroom — one corner of the Spanish-style, 7,500-square-foot Hollywood Hills home she shares with her parents, grandparents and an assortment of dogs, turtles and fish.

Every surface is covered with a memento or beloved treasure. Guitars hang from the walls, alongside vintage posters of “Jaws” and “Pulp Fiction,” and ads for Space Mountain and Snow White’s Adventures at Fantasyland. A white faux fur covered chair is filled with miniature plush toys.

A separate area, where Smith entertains friends, holds a bright orange table and refrigerator covered in stickers. Her pet rabbit, Cinnamon Bun, inhabits a hutch next to Smith’s four-poster bed.

Why is this your favorite room?

It’s the most “me” room I could ever imagine. It’s covered in animation cels from my favorite shows, posters of the bands I love, family photos — it’s everything about my personality. If you went in my room and did not know me very well, you’re going to get a sense of who I am very fast.

Do the pieces in here evolve?

I do change things, but there are some animation cels and stuffed animals I’ve had since I was a baby. Sometimes things go away but then they come back. I went through my emo phase where I put up posters of Iron Maiden and the Misfits, but then that passed.

So the room reflects where you are in your own life.

I go through lots of phases. Right now the space above my bed has lots of vintage photos of my family. Before that I was going through a basic phase where I printed out photos of the beach and had these Los Angeles collages. It was really lame.

Where did the love of collecting come from?

In my dad’s office he has buckets of tests he did in high school. He’s always kept everything. I’ve adopted that habit of not being able to let go of anything. I have a box of special things like wristbands from shows or cards someone gave me five years ago. My mother holds on to every single luggage tag so she can make a yearly family album.

And you feel like this room is your own space, even though you live with other people and all those animals?

I’m so close to my family and it’s important to me that we live together. The way the house is set up, it works for us because everyone has their own section. If we need space we have it, but when we miss each other I go upstairs and hang out with my parents or down the hall and watch a movie with my grandparents.

Are you always on the lookout for things for your room?

I go out sometimes with the intention of looking for something particular if I want a part of my life to be represented. I’ve purchased a lot from the Melrose Trading Post. You never know what you’re going to find there. Once my mother went to a thrift store and found a painting of a rabbit that looks exactly like mine. Sometimes it’s almost creepy because I’ll find something that is meant exactly for me.