Brennan O’Neill has gone viral. Multiple times, actually.

Last July, it was his back-down, behind-the-back stunner in the National Lacrosse Federation Championship game. The video made its rounds on Twitter and Instagram and blew up.

A couple of months later, he was back at it with a compilation of one-handed goals, powerful swim dodges and low-to-high shots as part of Inside Lacrosse’s Midnight Mania. The reaction, again, was fast and vast.

It’s amazing to see college players display these kinds of stick skills. But it’s another thing entirely when a 16-year-old high school kid from Long Island does it.

“I don’t know about my husband, but sometimes I’m like, ‘Did he really just do that?’ My jaw does sometimes drop,” says Diana O’Neill, Brennan’s mother.

O’Neill stands out not only for his exemplary abilities with a stick, but also because of his physical attributes. He stands at 6-foot-2 and has 230 pounds of muscle. Again, he’s 16.

O’Neill’s combination of size, strength and sizzle has many believing he isn’t just a top recruit, but also a generational talent.

“You could put him on a field with professional players, or play at the international level and he would score three or four goals in a game right now as a 16-year-old. He’s that good,” ESPN personality and former Syracuse All-American Paul Carcaterra says. “When I watch Mikey Powell, or Lyle Thompson or Brennan O’Neill play the game, there’s nothing traditional about their game. They’ve mastered the fundamentals, but their flair for the dramatic and ability to improv and make plays out of nothing is what separates them.”

O’Neill, a junior at St. Anthony’s (N.Y.) High School, was once the earliest boys’ lacrosse player ever to commit to a college program — making the pledge to Penn State as an eighth-grader in 2016 before flipping his commitment to Duke in September.

From many accounts, he has the makings of a great lacrosse player — a transcendent star like Powell, Thompson or John Grant Jr. With those comparisons comes pressure.

“Obviously, I love to see my shots go viral,” O’Neill says. “But it puts a lot more eyes on me and now that people know me, I’m going to have to play even better when I’m on the field.”

O’Neill has already garnered more attention than most high school players, and he’s got two seasons left. If he is indeed the next big thing in lacrosse, it’s because of two important traits — his ability to learn quickly and his extreme intrinsic motivation.

From an early age, O’Neill wanted to learn for himself.

“Even when I was teaching him to ride a bike,” says his father, Ed. “But he was like, ‘Hey, I want to do it by myself.’ He would go in the backyard and taught himself how to ride a bike. He’s always been that way.”

O’Neill’s self-motivation bled into sports at an early age. He started swimming when he was 6. He struggled, like all the children, in his first practice. But a week later, Ed and Diana saw him swimming laps.

He powered through swimming, hockey, basketball, baseball and football (his father’s former sport) before trying lacrosse. His parents knew nothing about the game, except that it was wildly popular in that region.

O’Neill joined the local Police Athletic League in second grade, learning the basic fundamentals of lacrosse like cradling and passing. But, again, he developed quickly.

“The first PAL game, they couldn’t really cradle,” Ed O’Neill says. “They did the spoon and no cradling. Probably the next game or the game after, somehow, some way, not by any doing of mine, something clicked. All of a sudden, I’m watching him and he’s actually playing lacrosse. The stick stuff came naturally to him.”

After games, O’Neill would come home to watch YouTube videos of Mark Matthews and John Grant Jr., then head out to the backyard to test their moves. He first tried a behind-the-back shot in a third-grade game when he was one-on-one with the goalie.

“I completely went out of my way,” he jokes. “I didn’t need to do it, but I did it anyway.”

Still, neither O’Neill nor his parents had any idea how special the kid could be. It took a meeting with coach Joe Spallina at a Pro Player Lacrosse Camp to give O’Neill that impression.

“We were searching for a left-handed attackman, and I had Brennan doing some stick skills,” Spallina says. “Right out of the gate, I call over my son, Joey, who was a 2022. I called Brennan over and I said, ‘Brennan, this is Joey. You two will spend the rest of the week hip-to-hip.’ From that point on, he’s been on my team.”

O’Neill joined Spallina’s club program, Team 91 Crush, where his game took off playing alongside some of the most talented prospects in the country. He could shoot 100 mph by middle school. His stick skills continued to develop.

But O’Neill always wanted more. He was lifting weights and doing pull-ups and sit-ups in the gym by sixth grade. Once he finished middle school and had committed to college, he was deadlifting and squatting.

“I realized how much stronger I was getting and how much that was helping me on the field, and how much stronger I was than the other kids that were guarding me,” he says. “I will never reach my peak, but I’ll continue to work my hardest.”

O’Neill and his father had gone to plenty of St. Anthony’s games during his childhood. By fifth grade, he was certain that’s where he wanted to play high school lacrosse. After leading Long Island with 99 points as an eighth-grader at Bay Shore High School, he made the move to St. Anthony’s. 

And it comes as no surprise that O’Neill has taken his budding lacrosse career to another level in his two seasons on the South Huntington, N.Y., campus. As a result, his phone was busy Sept. 1 of last year. O’Neill switched his commitment from Penn State to Duke, citing the Blue Devils’ track record of developing attackmen and the Long Island-heavy coaching staff, led by John Danowski, as factors in his decision.

What’s next for the nation’s most electrifying high school lacrosse player? The future looks bright, but O’Neill isn’t worried. He’s still looking for more. He practices five days a week and lifts at the same frequency. He can bench press 230, deadlift 240 and squat 360 pounds.

O’Neill is putting in the time to make sure that he lives up to the expectations placed upon him since he was a middle school student. But he’s still just 16 years old. He has two years left in high school. 

He has yet to get his driver’s license.

“He’s got his junior license and he’s so excited,” Diana O’Neill says. “We’ve been doing a lot of practicing parallel parking. He’ll get very mad at me if I say anything negative about his driving. He’s a wonderful driver. I can’t wait until he turns 17 and gets his full license and he can drive himself. I won’t be worrying.”

O’Neill has the attention of much of the lacrosse community, but he’s just hoping to enjoy his final two years of high school. There will be plenty more goals — plenty more times O’Neill will point one finger to the sky in his routine celebration.

When the lights aren’t on his lacrosse game, O’Neill likes going to the movies and occasionally playing video games with friends. But not “Fortnite.”

“That was so 2018. I got out of that,” he says. “I kind of got bored.” 

The future, as exciting as it might be, can wait for now.

“I’m a normal kid,” O’Neill says. “Sometimes people mistake that.”