When Megan Debin purchased her Long Beach, Calif., house in 2020, she found her backyard dreary with its cinder-block walls. Dr. Debin, an art history professor and content creator, was smitten with a light blue crab motif she had come across on Instagram. She asked its artist, Tracy Allen, a muralist in Long Beach, to paint the crab on one of her yard’s walls.

One mural turned into five — all different designs, predominantly blue — and now Dr. Debin, 45, sees her yard differently. “It’s so bright and playful, and it lifts your mood,” she said, adding that the murals inspired her to create an outdoor space where she could entertain among the yard’s orange trees.

Home murals were once relegated to children’s bedrooms, where they often tied into a theme. Today, they’ve grown up and taken over walls, indoors and out.

Technically speaking, a mural is a large work of art executed right on a wall. And while modern murals are typically associated with streetscapes and Insta-worthy backdrops, they’re one of the most primitive forms of artistic storytelling. In Dordogne, France, for example, the Lascaux cave paintings of about 15,000 to 17,000 years ago depicted horses, bison and other animals. And in Patagonia, Argentina, the “Cueva de las Manos” (“Cave of Hands”) is a composite of stenciled human hands that dates back at least 9,000 years.

“I think as humans we have this built-in tendency to share things with other people and do that in a visual way,” said Hailey Widrig, an art historian and founder of Art Partners Advisory in Paris, which advises collectors and appraises art works. “Murals really evolved out of that.”

The sprawling wall paintings have ebbed and flowed out of popularity through the centuries, from religious works in the Renaissance (like the “Last Supper”) to political statements by Diego Rivera in the 1930s and Banksy’s start in the 1990s. In the 2010s, destinations like Richmond, Va., which has hosted the RVA Street Art Festival since 2012, and Wynwood Walls in Miami began welcoming murals to add vibrancy and become attractions.

The rise of murals on social media has inspired homeowners to bring them indoors. “Platforms like Instagram have reframed murals as contemporary visual statements by transforming them from niche to aspirational through sheer exposure,” said Elena DeStefano, an interior designer in Philadelphia. “In response, designers began integrating them as immersive, site-specific works that introduce a unique narrative and spatial complexity into the home.”

That individualized touch is what makes Ms. DeStefano so inclined to incorporate murals in homes. “I think they work in literally any room with walls,” she said. “They are a true representation of the person that lives in that home because there’s no mural that is ever going to be the same.”

Ms. DeStefano is also a proponent of digital mural wall coverings by companies like Phillip Jeffries. She recently worked with a couple who wanted birds in their mural, and the company blended their designs and tweaked the scale of the birds to make a customized mural.

There are considerations to take into account before painting a mural. Diana Hathaway, an interior designer in the San Francisco Bay Area, suggested pulling in colors from the surrounding design to make the space cohesive. “It doesn’t have to be too literal, but it should echo something you already have going on,” Ms. Hathaway said.

Many see hand-painted murals as an alternative to wallpaper, which can be fussy to install — and not as unique. Some muralists paint designs reminiscent of wallpaper, like Kate White who lives in Garrison, N.Y. She specializes in retro hues and geometric patterns, such as a terrazzo-inspired bathroom mural or pink and yellow blocks in an entry hallway.

Even an often-overlooked area, like a stairwell, is not immune to a muralist’s palette. Kreh Mellick, an artist in Asheville, N.C., recently painted one in a family member’s home in Virginia. Ms. Mellick took the stairwell from plain to whimsical, adorned with stars and a dress-clad sun ascending over flowers and a blueberry patch.

In some cases, homeowners empower muralists to think beyond just painting the walls. Christina Kwan, a muralist in Atlanta, installed an oceanic mural-painting hybrid in a client’s dining room. “When I work on canvases, they’re so contained,” she said. “Then when I work on murals, they’re so expansive, but I want them to have the intimacy that a canvas does.” Additionally, if the homeowners ever move, they can bring the canvas with them, too.

Even in the modern era, murals tell stories. Rachel Kerns, a muralist in Sacramento with a flair for boho-chic florals, painted a dining room ceiling in Pasadena, Calif., last year. Among leaves and golden flowers set against a red backdrop, Ms. Kerns painted silhouettes of the homeowner’s children on the edge of the mural.

“We incorporated the silhouettes in a way that was kind of abstract and not too on the nose or cheesy,” Ms. Kerns said. “I just thought it was so special that it was above the table that they’re going to dine at for years.”