Some of these phenoms are already on our list of the 50 most dominant athletes alive.
Others, if everything works out, could be in the next few years.
While sports history is of full of examples of athletes that fail to live up to the hype, there are also stars like LeBron James, Tiger Woods, and the Williams sisters who actually met their astronomical expectations.
The so-called 'Greek Freak' was better in 2014-15 than anyone in the NBA expected. He has the height of a center, the skills of a guard, and an unreal 7'4' wingspan.
His potential is off the charts. He has been compared to everyone from Kevin Durant to Kevin Garnett. He has more raw physical talent than anyone else his age, and if he continues to develop, he could rule the NBA with Anthony Davis once the LeBron era comes to an end.
Odegaard, a Norwegian prodigy who burst onto the scene at age 15, had every big team in Europe clamoring for his services in January of 2015.
Soccer is full of examples of young players who fail to live up to the hype. Will Odegaard be different?
It's promising that he started Norway's most recent European Championship qualifier, and he bypassed the typically club progression and jumped straight to Madrid.
If there's one person you'd bet on being a star at the 2016 Rio Olympics, it's Biles.
Biles has been the most dominant force in women's gymnastics in the last two years. She won four golds at the last World Championships and the gold in the all-around competition in both 2013 and 2014. She's better than breakout star Gabby Douglas was when going into the London Olympics, and has a chance to take home a boatload of medals.
In a sport where players can compete at a high level well into their 40s, Jordan Spieth might be a part of our lives for the next two decades.
With one of the great Masters performances ever already under his belt, Spieth has all the tools you look for in a great golfer. He's not obscenely long off the tee, but he's an unreal putter and he's only going to get better.
Even though his rookie season started off with controversy, the No. 1 prospect in baseball looks like a future superstar. He hit 43 home runs in the minors in 2014. In his first 10 games for the Cubs, he hit a ridiculous .351 with nine RBI.
Unlike fellow phenom Bryce Harper, Bryant is a relative late bloomer. He wasn't drafted until the 18th round coming out of high school, and didn't blow up until he got to the University of San Diego. Now, though, he's looking like the centrepiece of a resurgent Cubs team.
McDavid, a prospect so good teams were tanking for him, is perhaps the most hyped prospect since Sidney Crosby. Before his 17th birthday, USA Today called him 'the LeBron James of hockey.'
Barring unforeseen circumstances, McDavid will be drafted No. 1 overall by the Edmonton Oilers -- a franchise that hasn't been to the playoffs in nearly a decade.
After winning a gold medal at age 15 in London, Ledecky blossomed into perhaps the best women's swimmer in the world in 2014. She broke five world records and won five gold medals at the Pan Pacific Championships.
She'll be in her absolute prime in time for the Rio Olympics, where she should be one of the breakout stars.
To be honest, Lydia Ko has kind of already taken over the women's golf world.
She's already No. 1 in the world (for two years running). At 17, she already has seven career wins and nearly $US3 million in career earnings.
The last mountain for her to climb is majors. She only has one top-10 in 11 career starts at majors. That stands to change soon.
The two-time national player of the year is one of the best players in the world and she's not even out of college yet.
She's often compared to Kevin Durant, with the height to beat defenders in the post and the skill to attack from the perimeter. With one year left at UConn, she has a chance to win three-straight POY awards and four-straight national championships.
The Croatian teenager has been hailed as 'the next Novak Djokovic' as he vaulted up the world rankings in the last year.
He's now No. 55 after starting last season at No. 301, and has wins over Rafael Nadal and Andy Murray.
Alvarez hasn't even reached his peak, but he already has the record for biggest pay-per-view ever by revenue (thanks, Floyd Mayweather). While he lost that fight in convincing fashion, it's the only loss on his record and he has more name recognition at his age than anyone else in the sport.
In the rich history of Mexican boxing, he's the next man in line to the throne.
As American men continue to struggle, the future for US women is bright. Keys is at the head of that charge. She's up to No. 17 in the world after being stuck in the 30s since 2013.
Her coming out party came at the 2015 Australian Open, where she made a run to the semifinals before losing to eventual champion Serena Williams.
Schiffrin is already the best slalom skier in the world. She won four slalom World Cup events in 2015 alone, including a gold in the World Championships in Colorado.
Her gold medal at the Sochi Olympics could be just the beginning. She should still be in her prime at the 2018 Olympics and maybe even 2022.
With some of the most famous sprinters in the world getting up there in age, there is plenty of opportunity for an up-and-coming to steal some headlines going into the Rio Olympics. Enter Bromell.
After running a wind-aided 9.77-second 100 meters that wasn't eligible for any world records, he broke the world junior record in the 100m. He's still young for a sprinter, but if he continues to develop he could be huge.
Hanyu pretty much already owns the men's figure skating world. He set the world record for highest score in the short program at the Sochi Olympics, winning the gold medal with ease.
Since Sochi he has faced a bit of adversity. He got injured in a freak collision at the Cup of China in November 2014, but a few months later he finished second in the World Championships.
Does Jones still count as a phenom if he was much older than most freshmen when he led Ohio State to a national championship?
We vote yes. He shocked the NFL world by returning to school following the title. If he wins the QB job and has another stellar year, he could be a top pick in 2016.
NOW WATCH: Briefing videos
Business Insider Emails & Alerts
Site highlights each day to your inbox.