You know Katie Ledecky, Simone Biles, Allyson Felix and the other household names competing in the Summer Olympics.

Before the opening ceremony Friday marks the official start of the Games, get to know the teenage athletes who could medal in Tokyo and contend for titles for years to come.

1. Katie Grimes, 15 

Country: USA

Event: Swimming

About: At the young age of 15, Katie Grimes was the breakout star at the U.S. Olympic Swim trials. She’ll be competing in the women’s 800-meter freestyle in Tokyo alongside highly-decorated Olympian Katie Ledecky. Grimes is the youngest swimmer to make the Olympic team since Ledecky in 2012. Even Ledecky is already singing Grimes’ praises, saying she’s “the future,” and “the now.”

2. Athing Mu, 19

Country: USA

Event: Track and Field

About: Fresh off of breaking the Olympic Trials track record in the 800-meter dash, Athing Mu is being touted as the country’s next great middle-distance runner. Mu, who competed at Texas A&M before turning pro this summer, holds NCAA records for both the 400 meters (49.57) and the 800 meters (1:57.73). In regards to feeling pressure as a running prodigy, Mu says, “I take everything that people say lightly. I don’t let it get to my head.”

19-year-old @athiiing sets the Trials record and punched her ticket to Tokyo! 🎟@usatf | #TrackFieldTrials21 x #TokyoOlympics pic.twitter.com/luuwJoUHnS

— #TokyoOlympics (@NBCOlympics) June 28, 2021

3. Hannah Roberts, 19

Country: USA

Event: Cycling

About: BMX Cycling is making its Olympic debut in Tokyo, and so is Hannah Roberts. Roberts is a highly decorated star on the BMX freestyle circuit. In 2019, she won all three World Cup events in addition to her second world championship. Roberts is a gold-medal favorite in her event in Japan, and she could become the first teenage woman to win an Olympic cycling medal.

4. Hend Zaza, 12

Country: Syria

Event: Table tennis

About: Representing Syria, 12-year-old Hend Zaza is set to be the youngest Olympian in 52 years. She’s also beating the odds: Zaza has been able to participate in only two or three external matches a year due to war. If you haven’t watched table tennis before, Zaza’s stellar talent will make you want to follow this Olympic sport in Tokyo.

5. Torri Huske, 18

Country: USA

Event: Swimming

About: Having just graduated from high school and heading to Stanford next year, Torri Huske managed to break the 100-meter butterfly record twice at the Olympic swimming trials last month. Twenty-four hours after she broke the U.S. record in prelims by .20 seconds, she broke her own record again. Starting off as a “normal little kid who worked hard,” she will now be one of 11 teenagers to compete for the U.S. swimming team in Tokyo.

6.Grace McCallum, 18

Country: USA

Event: Gymnastics

About: Grace McCallum was named to the four-person team representing the U.S. at the Summer Olympics following the national trials in June, an achievement that seemed nearly impossible when she broke her hand earlier in the year. McCallum, who had already competed at the U.S. Classic and the National Championships, finished fourth at the Olympic Trials. The 18-year-old’s specialties include uneven bars and balance beam.

7. Caroline Marks, 19

Country: USA

Event: Surfing

About: Surfing standout Caroline Marks took the world by storm in 2018. In her breakout year, as the youngest surfer ever to qualify for the Women’s Championship Tour, Marks was named Rookie of The Year and finished with a No. 7 world ranking. Now ranked sixth on the Championship Tour, Marks spoke with Just Women’s Sports about her rapid ascension to the top of her sport.

It's not long before 19-year old @Caroline_Marks3 makes her debut on the global stage. Surf fans everywhere are in for a treat.
Video: Swellshotz pic.twitter.com/ulyQ2E9OJ8

— World Surf League (@wsl) July 16, 2021

8. Kokona Hiraki, 12

Country: Japan

Event: Skateboarding

About: At the age of 12, Kokona Hiraki will be one of the host country’s youngest and most admired stars. After ranking fifth at the final Tokyo Olympics qualifier for women’s park skateboarding, Hiraki will now be the youngest Japanese Summer Olympian ever. Her dedication to her craft is next level: After practicing a nosegrind trick over and over again, Hiraki wrote, “You can feel all the things I love about skateboarding through this trick. The unstableness from being just on the front truck on the coping, the sound of grinding, and the satisfaction when you make it.”

9. Nevin Harrison, 19

Country: USA

Event: Canoeing

About: Canoe sprint world champion Nevin Harrison is heading to the Tokyo Olympics with high expectations. In 2019, she became the first American to win a world sprint canoe title by clinching the women’s C1 200-meter event. Harrison is also a strong advocate for women’s canoeing’s inclusion in the Olympics, saying, “I think it’s more important to have every group represented rather than having a lot in just one gender or discipline,” Harrison said.

10. Sunisa Lee, 18

Country: USA

Event: Gymnastics

About: After coping with family illness, COVID-19 related deaths, and injury, Sunisa Lee claimed a coveted spot on the U.S. women’s gymnastics team by finishing in the top two at the Olympic trials. “It’s the unparalleled mental strength that she has shown during the most difficult time of her life that makes her the person she is,” said 2008 All-Around champion Nastia Liukin. Lee, whose parents emigrated from Laos, will be the first-ever Hmong American Olympic gymnast. While she’s an incredible all-around talent, she’s especially known for her bar routine.

11. Sky Brown, 13

Country: Great Britain

Event: Skateboarding

About: Sky Brown is arguably one of the biggest and brightest stars of any age at this year’s Olympics. At just 13 years and 11 days, she’ll be the youngest Summer Olympian for Great Britain. A fearless and promising athlete, Brown is currently ranked fourth in the world and is highly respected in the skateboarding community. “She could definitely be one of the best female skaters ever… she has such confidence, such force, even at such a young age. The way she’s able to learn new tricks and the way she absorbs direction, it’s so rare,” said skateboarding legend Tony Hawk.

Sky Brown 🇬🇧 wins gold in Women’s Skateboard Park at #XGames 2021! pic.twitter.com/LcGC5OqENB

— X Games (@XGames) July 16, 2021

12. Jessica and Jennifer Gadirova, 16

Country: Great Britain

Event: Gymnastics

About: 16-year-old twin sisters Jessica and Jennifer Gadirova will be each other’s support systems in Tokyo, as they will represent half of Great Britain’s four-person gymnastics team. Jessica flourished at the 2021 European Championships, where she won the bronze in the all-around and silver in vault, and she became the European champion in the floor exercise. Jennifer, a strong vaulter and floor gymnast, is known for her difficult tumbles and eye-catching choreography.

13. Viktoria Listunova, 16

Country: Russia

Event: Gymnastics

About: The postponement of the 2020 Olympics allowed 16-year-old Russian gymnast Viktoria Listunova to be eligible for the 2021 Olympics. “It’s such an opportunity, it is such a big chance,” Listunova says. She is determined to make the most of this opportunity and is considered a possible contender to upset world champion Simone Biles.

14. Rosalie Boissoneault, 18

Country: Canada

Event: Synchronized Swimming

About: A native of Québec, Canada, Rosalie Boissoneault joins the Canadian synchronized swimming team as one of its newest members. She is making her Olympic debut at just 18 years old after joining the senior national team in 2020. Starting in her sport at the age of 3, Boissoneault is a young star looking to make a splash in Tokyo.

15. Rayssa Leal, 12

Country: Brazil

Event: Skateboarding

About: Another young Olympic phenom and friend of Sky Brown is Brazilian skateboarder Rayssa Leal (pronounced “Hi-ee-sa”), known for her many viral trick videos. She is currently second in the World Street Skateboarding rankings. Giving props to her supportive family, Rayssa says, “they don’t pressure me to always win and be first, they encourage me to do what I like, which is skateboarding.”

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16. Regan Smith, 19

Country: USA

Event: Swimming

About:  Regan Smith, the current world-record holder in the women’s 200-meter backstroke, is heading to her first Olympics to represent Team USA. This young star showed off her talent during the World Championships in 2019, where she broke two world records: the 100- and the 200-meter backstroke. Smith will be taking a gap year and plans to attend Stanford in 2022.

17. Brighton Zeuner, 17

Country: USA

Event: Skateboarder

About: Zeuner is coming to the Olympics as a decorated skater with serious competitive chops. She’s the youngest recipient in history to have won two X Games gold medals, and she also holds a Vans Park Series World Championship title. Her great passion and love for skateboarding pushed her to keep going and get her to where she is now. ‘”I love it. Because of skateboarding, I’m kind of who I am. I get validation out of it. It makes me feel human. It’s just a part of me,”’ Zeuner said.

18. Hailey Hernandez, 18

Country: USA

Event: Diving

About: Hailey Hernandez started competing right out of high school and surprised the diving world by placing second in the women’s three-meter springboard at the Olympic trials. “When I hit that water, I knew that I had done it and so I just had the biggest smile on my face,” Hernandez says. Her hometown in Southlake, Texas, threw the two-time World Junior Championship silver medalist an epic Olympic send-off event and will be rooting hard for her this summer.

19. Gaurika Singh, 19

Country: Nepal

Event: Swimming

About: Nepali swimmer Gaurika Singh will represent her country both in the pool and as the flag bearer. The 19-year-old was the youngest athlete at the 2016 Rio Olympics at 13 years and 255 days, and she was chosen to lead the five-member Nepali team in the opening ceremony this year. Singh has collected over nine medals during the South Asian Games and set a record for the most gold medals in 2019.

20. Oceana Mackenzie, 19

Country: Australia

Event: Sport Climbing

About: Australian sport climbing star Oceana Mackenzie will help introduce this new Olympic sport to the world. She started climbing at age of 8 and has been passionate about it ever since. “I love how it’s mentally and physically challenging,” she says. “I have to see the climbs and figure out how to get up them — it’s almost like working out a puzzle.”

With the 2025 NCAA gymnastics season in full swing, top collegiate athletes are already eyeing mid-April's national championship in Fort Worth, Texas.

Unlike elite gymnastics, where difficulty can outweigh execution, the college level values precision over big tricks, so Division I athletes all aim for perfect 10s in their competition performances.

Despite this difference, many of the world's most decorated elite gymnasts also compete in the NCAA. Two-time Olympian Jade Carey is back for her senior season with No. 14 Oregon State while her US teammate in both Tokyo and Paris, Jordan Chiles, is entering her junior year at No. 11 UCLA.

The Bruin, who took the 2024 NCAA season off to prepare for last summer's Olympics, will attempt to reclaim the national titles on uneven bars and floor exercise that she earned in 2023.

Top teams poised for the podium

After earning their first national title last spring, No. 2 LSU is hitting the 2025 mat armed with a stacked roster, headlined by 2024 all-around champion Haleigh Bryant and social media star Livvy Dunne.

Add in last year's freshman phenom Konnor McClain, whose prowess on the balance beam ultimately clinched LSU the NCAA trophy, and 2024 Olympic alternate Kaliya Lincoln, who opened her NCAA career with a 9.825 vault two weeks ago, and the Tigers are more than capable of a back-to-back run.

LSU isn't the only SEC team predicted to make a deep run this season, as the conference is once again flush with perennial contenders.

Elite US stars Kayla DiCello and early Freshman of the Year frontrunner Skye Blakely will join two-time US Olympic alternate Leanne Wong in trying to return No. 7 Florida to the NCAA championship meet. At the same time, new SEC team No. 1 Oklahoma, winner of seven of the last 10 NCAA trophies, could see senior Jordan Bowers de-throne Bryant for the 2025 all-around title.

Also causing early national championship chatter are 2024 finalists No. 5 Cal, who return two of the country's best all-arounders in senior Mya Lauzon and junior eMjae Frazier, and Big Ten champs No. 6 Michigan State, whose veteran-heavy lineup boasts stars Skyla Schulte and Sage Kellerman.

How to watch NCAA gymnastics this weekend

Some of the country's top NCAA gymnasts will take the mat when No. 7 Florida visits No. 2 LSU at 7:30 PM ET on Friday. Live coverage will air on ESPN2.

The NCAA unanimously approved implementing a women's March Madness revenue-sharing plan on Wednesday, aligning the women's side with the compensation program the men’s edition has enjoyed since 1991.

"This is a historic day for women's sports, women's basketball, and the NCAA," said NCAA president Charlie Baker in the college sports governing body's statement. "Today's vote means our members have the opportunity to do even more on campus to promote and support female athletes. I can't wait to see all the incredible things they do."

Sparked by 2021's landmark NCAA gender equity review, the decision ultimately actualized after years of pressure from administrators and coaches.

"The long-awaited, hard fought for, and well-earned day is here," said UNC coach and Women's Basketball Coaches Association president Courtney Banghart. "I am so grateful for the effort of so many to bring this reality to our sport."

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Deep March Madness runs earn more revenue

Beginning this year, each team competing in the Division I tournament will now receive performance-based units of revenue, with deeper runs earning more units.

With plans to grow the prize pool to $25 million by 2028, this year's inaugural $15 million purse represents 26% of the competition's $65 million media rights valuation — putting it proportionally on par with the percentage allocated to the men's fund.

Distributions will begin in 2026 and, like the men’s program, they will be paid directly to conferences, whose member schools will collectively decide how to best invest the unrestricted funds.

For the 2025 edition, a unit will reportedly be worth $113,636. According to ESPN's calculations, a Final Four team could amass approximately $1.26 million for its conference over the next three years.

With conferences and schools set for an influx of funds should their teams flourish at the national tournament, the revenue plan becomes a significant incentive for institutions to further invest in women's basketball.

Ultimately, the NCAA's move not only addresses the sport's equity disparity, it could also bolster the annual tournament's level of competition.

Unrivaled basketball hits the court for the first time on Friday and, according to ESPN, the debut league's style of play will look a little different from the 3×3 Olympic game's rules.

Unlike the half-court version currently played in major international 3x3 basketball competitions, Unrivaled's full-court edition uses slightly smaller court dimensions from a traditional 5×5 setup.

Similarly, the inaugural league's format follows a four-quarter setup, but opts for seven-minute periods rather than the WNBA's 10-minute quarters. The shot clock will also be a speedier 18 seconds versus the professional 5×5 game's 24 seconds.

Unrivaled victories, however, rest solely in fourth-quarter play. This "winning score" quarter denotes that the win goes to the first team to score 11 more points than the highest final third-quarter score. For example, if a game's third quarter ends with a 45-43 scoreline, the first team to post the target score of 56 points in the final period walks away with the victory.

This system essentially eliminates the possibility of overtime. League organizers also hope it deters the late-game fouls used strategically and prolifically in 5×5 contests.

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Unrivaled 3×3 format revamps fouls

Speaking of fouls, Unrivaled is also condensing the free throw system to keep the game moving. Each player has six fouls to give, but each shooting foul will earn a single free throw at the line.

Those awarded free throws, however, will contain different point opportunities depending on the foul incurred. Fouled two-point shots grant a single free throw worth two points, while a free throw awarded from a three-point attempt will be worth three. All and-ones are worth one point.

With six players rostered on each of Unrivaled's six teams, the league also tweaked the traditional rule of fouling out to ensure games can be completed should they become especially chippy. If an athlete fouls out with only three available players left on their team, that player can continue competing. She will instead incur a technical foul — resulting in one opponent free throw — for each additional foul.

The new league's rules all point to Unrivaled's efforts to put an engaging, fast product on the court.

"This game is rooted in how you would play basketball as a kid on a black top," Unrivaled president of basketball operations Luke Cooper told ESPN's Kendra Andrews on Tuesday. "There's flow, there's pace. When you are watching, it feels like you are watching basketball... it's not a gimmick."

The WNBA free agency carousel started spinning this week, with teams evaluating rosters and coring athletes to either retain talent or trade players for a return.

Thus far, cored players include Las Vegas Aces guard Kelsey Plum, New York Liberty forward Breanna Stewart, Dallas Wings forward Satou Sabally, and Seattle Storm forward Gabby Williams.

Squads employ single-use coring on WNBA stars

Each of the WNBA's teams can core one unrestricted free agent on their roster, ensuring them exclusive rights to that cored athlete. Cored players receive an offer for a one-year, supermax salary contract, along with the option to negotiate different terms.

Cored athletes are unable to directly sign with another franchise, but they can be part of a trade offer by their coring team.

New York cored Stewart after she expressed interest in remaining with her 2024 WNBA Championship-winning squad. Sabally, on the other hand, will likely be part of a sign-and-trade deal after telling media late last week that she is looking to leave Dallas in 2025.

Plum's situation with the Aces is less clear-cut: The two-time WNBA champion could re-sign with her team, though Las Vegas could be exploring opportunities to cash in should she want to compete elsewhere.

Other offers spark WNBA free agent negotiations

In addition to coring, WNBA teams have also begun sending qualifying offers to certain restricted free agents, allowing them to initiate negotiations with those players.

Most notably, despite making Monday offers to three players — guard Dana Evans, forward Michaela Onyenwere, and forward Nikolina Milić — Chicago has yet to extend a qualifying offer to the Sky's 2024 points-leader Chennedy Carter.

Ultimately, while negotiations kick off next week, WNBA contracts cannot be finalized until free agency revs up in February, meaning more shuffling is on deck as teams gear up for the longest and most competitive roster-building season in recent memory.