With more than 400 million viewers, Formula 1 is one of the most popular sports in the world. Yet for many years it was all but unknown in America.

But reality TV changed all that.

Since the Netflix series “Drive to Survive” — featuring behind-the-scenes footage of the usually-secretive racing teams and the sometimes contentious relationships between drivers and team executives — debuted in 2019, the American audience for Formula 1 has skyrocketed.

Netflix doesn’t publicize viewer data, but the audience for ESPN’s coverage of Formula 1 races has nearly doubled — up to 1.5 million views per race — since the show premiered.

According to a recent Nielsen study, Formula 1 is on track to top a billion worldwide fans this year, with 77 percent of those new fans under 35 years old.

“Without ‘Drive to Survive’ there would be no American F1 boom,” Kevin Clark, host of The Ringer’s F1 Show, told The Post. When his podcast started, the idea was to recap episodes of the binge-worthy show and preview each of the 22 races in the sport’s season. The success of the podcast caught him and the staff of The Ringer, a popular sports and pop culture site, by surprise, however.

“When we saw the numbers, we saw the reaction,” Clark said. “We knew this wasn’t going to be a part time thing. We tapped into something.” According to the podcast rankings at Chartable, The Ringer F1 Show is regularly among the top 50 sports podcasts in the United States. 

Formula 1 has gotten so big that Sun., May 8, marks the inaugural Miami Grand Prix, which will be run in the Hard Rock Stadium — complete with a makeshift Monaco-style marina for yachts built just for the occasion — and has ticket prices rivaling the Super Bowl.

“You look at Formula 1 and it’s healthier than it’s ever been before. We’re selling sold-out tickets, so far, everywhere, and I think it’s going to continue the whole of this year,” driver Alex Albon — a “Drive to Survive” star — told Page Six during the Williams Racing launch party at the W Hotel South Beach on Thursday.

In another sign that “Drive to Survive” is fueling the new American Formula 1 fandom, the Miami Grand Prix driver’s parade — a pre-race tradition of the sport where drivers travel the circuit out of their cars so fans can see them up close and personal — will, for the first time, include Team Principals, the executives who have become celebrities on the show.

Miami is actually the second American race: The US Grand Prix, run in Austin, Texas, since 2012, saw a 15 percent increase in attendance in the first year of “Drive to Survive,” with 250,000 fans attending the race — a number on par with a typical Kentucky Derby crowd. In 2021, that number had grown to over 400,000, making it the largest crowd at a Formula 1 race anywhere in the world, ever.

Next year there are plans to add a third American stop and race cars down the Las Vegas Strip.

“I started watching ‘Drive to Survive’ three months ago and I went from actively disliking motorsports to being obsessed with F1. I read about it every day, I’m on the Reddit every day, I text about it every day, I think about it every day,” television writer Travis Helwig, 34, told The Post. “Like most sports, the best part is the narrative, and Formula 1 lends itself to the drama and narrative well. There’s only 20 participants, so it’s easy to learn every participant’s story.”

American-based Liberty Media Group purchased Formula 1 for $4.4 billion in 2016 and partnered with Netflix in a radical departure from anything the brand had done before.

“Drive to Survive” is unique, according to Clark, even among sports reality shows. While HBO’s NFL reality series “Hard Knocks” gives the NFL final say over what is broadcast, Netflix has no such agreement with Formula 1,

The result, Clark added, is a much more revealing and entertaining show, and one that draws in fans who not only never watched Formula 1 before, but never even watched sports at all.

“Reality shows — even if you think they take away from the competitive element, even if you think that it makes a mockery of the sport — it’s the easiest way to create superstars,” Clark said. “Tens of millions of people have watched ‘Drive to Survive.’ And there are so many people who did not like sports who are now watching this every single weekend.

“The switch between how F1 markets itself is an entertainment product was a huge inflection point in the sport.”

“I didn’t care about F1 at all. After watching ‘Drive to Survive,’ I will now teach my [future] children about F1,” said Alexis Novak, 31, the founder of the online clothing store Tab Vintage. “It made me feel giddy and made me want to follow and support my favorite drivers like I used to with boy bands.”

For Novak, who says she has always “actively disliked sports,” “Drive to Survive” made Formula 1 seem different. “It’s not like other sports because you get to know the people in the cars, the people working on the cars, and the owners. You get to see the politics behind the races too,” she said. “It’s a perfect crossover of culture, wealth, fame, adrenaline and drama —like the ‘Real Housewives’ meets the Super Bowl.” 

Former Formula 1 chief executive Bernie Ecclestone was famously dismissive of younger fans.

“I don’t know why people want to get to the so-called ‘young generation,’” Ecclestone told Campaign Asia-Pacific magazine in 2014. “Why do they want to do that? Is it to sell them something? Most of these kids haven’t got any money. I’d rather get to the 70-year-old guy who’s got plenty of cash.”

The impact of the growing American audience is being felt around the world, too.

“Forty percent of our audience is from the US now, and only 25 percent is from the UK,” said BBC radio presenter Richard Ready, host of the Formula 1 podcast “Missed Apex.” “So if people want to get snobby about ‘Drive to Survive’ fans, they have to kind of realize they’re a bit outnumbered now.”

Ready is referring to a growing concern, particularly among some European fans of the sport, that these new fans are going to “Americanize” it: putting an emphasis on personalities, exaggerating rivalries and minor disputes and fulfilling the American need for all sporting contests to be dramatic and decisive.

“Americans cannot abide a tie,” Ready says. “Formula 1, to me, is sometimes special because nothing happens. And that might be a British thing or a European thing. In soccer, we don’t mind the odd boring draw … If you force the spectacular all the time, it’s like having birthday cake every day. So when your birthday comes around, is it that special?”

The fear that playing to the American audience’s appetite for drama came to a boil in last year’s final race in Abu Dhabi, where the two top drivers were tied in points for the championship. After it looked like the race would be decisively won by reigning champion Lewis Hamilton, a controversial decision by the Race Director Michael Masi allowed challenger Max Verstappen to close the gap and win in the final lap of the race.

The result was a thrilling neck-and-neck finish, but longtime fans of Formula 1 cried foul, saying Masi broke the rules. An investigation by the FIA, Formula 1’s governing body, found that Masi’s decision was the result of “human error” and he was replaced as Race Director. Many fans wondered if that error was the invisible hand of Netflix guiding the race results.

“There was already a suspicion going into that, that there’s been a Netflix-ization of the sport,” said Clark. “I think what you saw in Abu Dhabi was just general run of the mill incompetence, but because there was already a skepticism among diehard fans, you saw more theories about that.”

“I do not see that as a conspiracy theory,” Ready arued. “I see it as very plausible.”

Netflix just confirmed confirmed two more seasons of “Drive to Survive,” and producers have been spotted at Formula 1 races this season.

“Formula 1 now, I have to say, is an American sport,” Ready admitted. “And as much as the things that are coming in from the US might be jarring to us, F1 did need them.”