Data: NFHS; Map: Brad Jennings/Axios Girls flag football has become the fastest-growing high school sport, as tens of thousands take up a game that barely had a varsity footprint a few years ago. Why it matters: Few girls high school sports have moved from niche to mainstream so quickly, broadening athletic opportunities in the process. By the numbers: More than 102,000 girls played high school flag football in 2025-26, a 551% increase in the past four years, according to the National Federation of State High School Associations. Catch up quick: In 2024, just 12 states sanctioned high school girls flag football, viewed as a safer, more accessible version of America's most popular spectator sport. Today, 23 states plus Washington, D.C., sanction it as an official varsity sport, and 3,990 schools reported participants in 2025-26. The NFL is backing its growth, too. It has invested millions to launch and expand high school programs, and featured the sport in its Super Bowl commercials. Beyond high schools, flag football will debut at the 2028 Olympics, and at least 40 NCAA schools already offer it as a collegiate varsity sport. Reality check: It's not yet clear whether flag football is mostly creating new high school athletes or pulling girls from established sports. A recent Newsday analysis on Long Island found flag participation rising sharply while girls lacrosse, softball and track participation fell. What we're watching: Girls varsity wrestling is undergoing its own boom. All 50 states now report girls wrestling participation, and 40 state athletic associations hold girls wrestling championships, up from just five about a decade ago.