Move over, Bollywood. There’s a new star in town called Tollywood

Manoj Valluri, chief executive of a Hyderabad-based social-media marketing firm, says he’s given up trying to squeeze productivity out of his workers on certain key days. These aren’t official holidays—he means the opening days for the latest South Indian blockbuster action-hero films.

Swaths of the region come to a standstill for the kickoff of the star-laden movies. Some companies give their employees the day off because they know many will play hooky to watch megawatt actors punch, kick and outwit the bad guys on the big screen.

Mr. Valluri offers his 23 employees a holiday and free movie tickets to boot. The 32-year-old boss admits he doesn’t miss a new film himself. He might also partake in tossing flowers at the stars on the screen, as well as blowing off some fireworks after the closing credits.

“I know how they feel,” he says of his employees. “At any cost, I will go on that first day.”

India is known for its Bollywood movie industry featuring Hindi-speaking actors who dance and sing their way through over-the-top romantic extravaganzas. That nickname is a portmanteau of Bombay, a center of filmmaking that is now called Mumbai, and Hollywood.

But nearly 60% of Indians don’t count Hindi as their primary language—and this huge audience has sparked the enormous growth of “Tollywood,” a competing industry of South Indian films and television shows that derives its name from its use of Telugu, one of the region’s major languages.

Tollywood devotees are thrilled to have big-budget, swaggering blockbusters in their mother tongue. The genre has also inspired a level of hero worship some observers describe as simply bonkers.

For premiere days, fans often hire marching bands to play outside theaters and create towering multistory wooden structures in the likeness of their favorite stars, and then smother the structures in flower garlands and confetti.

They also indulge in a version of a ritual usually reserved for idols of Hindu gods: pouring thousands of gallons of milk on cutouts of adored actors, including 71-year-old South Indian actor Rajinikanth, who, like Cher, goes by one name, although in his culture it’s common. At least 20,000 gallons of milk are spilled in the south Indian state of Tamil Nadu whenever a Rajinikanth movie debuts, according to the state’s milk dealers association.

Rajini Santosh, a 40-year-old architect from Bangalore, says he can’t help himself, even after the actor begged fans to stop wasting milk.

“We are emotional fools on the day of openings,” Mr. Santosh adds.

Avinash Varma, a 30-year-old writer from Hyderabad, says so many people cheer and throw confetti at the movie screen on opening day, it’s impossible to follow the plot or hear much dialogue.

“Nobody understands a word in the movie,” Mr. Varma says.

Movies made in the Telugu-language studios of Tollywood, centered in the southern city of Hyderabad, and in the Tamil language, recently have trounced Hindi films at the box office by pulling in 46% of total ticket sales compared with 27% for Hindi-language flicks in 2020 and 2021, according to consulting firm Ormax Media. Major streaming platforms, such as Amazon.com and Netflix, are scrambling to capitalize on the booming audience by investing in television shows in South Indian languages.

India is a country of movie buffs, and industry experts say the love for films runs especially deep in South India, where single-screen cinema halls hawking cheap tickets dot even small towns. Of the 9,300 movie screens in India, about 45% are located in just five South Indian states, including Tamil Nadu, Telangana and Karnataka, says Akshaye Rathi, a film exhibitor who operates 14 theaters in the states of Maharashtra and Chhattisgarh.

Over the past few years, Tollywood films have crossed borders and captured audiences by doubling down on fare appealing to many Indian viewers: spectacles in which an underdog battles his way to the top of his chosen field. Recent popular characters have included a freedom fighter, crime boss, and village chief.

“Tamil and Telugu cinema continue to cater to the commonest of common people,” says Mr. Rathi.

Many Bollywood actors alienate viewers by flaunting their jet-setting and designer-clad off-screen lifestyles, adds Mr. Rathi, while South Indian megastars tend to keep public behavior circumspect and modest.

Yash, who stars in the South Indian hits K.G.F: Chapter 1 and Chapter 2, makes sure to greet and thank the thousands of fans who gather outside his Bangalore home on his birthday. One admirer rented a helicopter to toss flowers onto cinema halls when a recent film premiered.

“Everywhere people like me,” says Yash, who legally changed his name to the one word. “They love me.”

The entire city of Bangalore, a major tech hub, shut down nonessential businesses for a day in October after a 46-year-old actor died of a heart attack. Restaurants, bars, and retail stores were all ordered to close to prevent mayhem from grief-stricken fans. Soumya Shukla, a 24-year-old model from New Delhi, was in Bangalore for an engagement party when the shutdown orders flashed on Twitter.

“I thought it was a prank,” Ms. Shukla says, adding that the engagement fete was thrown into utter chaos.

The reverence makes sense to fans. Anitha, a 28-year-old Hyderabad-based lawyer who goes by one name, is a huge fan of Tollywood actor Ram Charan. She enjoyed the hunky actor’s portrayal of a policeman battling sadistic British colonial administrators in the blockbuster flick RRR. (His sense of style and smart persona off-screen also helps, she says)

So naturally, she included him in her wedding in May.

She added photos of Mr. Charan and his family to the roughly 3,000 wedding invitations she sent out. On the cards, bordered with yellow and white roses, the bearded actor and his beaming wife appeared above a line blessing the big day. Ms. Anitha says most of her guests were pleasantly surprised to see the famous faces peeking out of envelopes—and she was thrilled. “I loved it!” she says.