Many of them will come together on March 24 for March for Our Lives, a demonstration in Washington and hundreds of other cities around the world demanding immediate legislative action to curb gun violence.
Here's a look at some of the people and groups you'll want to know ahead of the event.
Stoneman Douglas student survivors
The students who were inside Marjory Stoneman Douglas on the day that 17 of their peers and teachers were gunned down have since emerged as some of the most visible voices for change.
Days before the march, Time magazine unveiled a cover featuring Jaclyn Corin, Emma Gonzalez, David Hogg, Cameron Kasky and Alex Wind, but they're just a handful of the large group student activists who have heeded a call to action in the wake of tragedy. Other students like Sarah Chadwick, Delaney Tarr, Lex Michael and Carly Novell have also been outspoken on social media since the shooting, and the teens have collectively garnered more than a million followers.
While specifics have not yet been released, many of the Stoneman Douglas students are expected to appear and speak at various events throughout the country.
In keeping with the march's theme as a student-organized event, the lineup of speakers in Washington is comprised of teenagers from around the country who have been impacted by gun violence. Event organizers have not disclosed exactly who those speakers will be (only that there are 17 of them in honor of the 17 killed in Parkland), though some of the prominent Stoneman Douglas students are expected to speak.
Other cities across the country have adopted different approaches for their independently organized marches. Amy Schumer, Connie Britton and Skai Jackson are among those expected to speak in Los Angeles, while various gun reform advocates will speak in New York.
Miley Cyrus, Common, Jennifer Hudson, Lin-Manuel Miranda and other performers
Numerous celebrities have lent their support to the students' cause, and nine big names have agreed to perform at the main rally in Washington. Jennifer Hudson, Common, Miley Cyrus, Vic Mensa, Ariana Grande, Andra Day and Demi Lovato are all set to hit the stage in the nation's capital.
Broadway stars Lin-Manuel Miranda and Ben Platt have also signed on to perform. Earlier this week, the duo released a mashup combining songs from their wildly popular shows "Hamiton" and "Dear Evan Hansen," proceeds from which will benefit the march.
Stoneman Douglas victims
Much like the school walkouts and other demonstrations that have taken place, the marches are expected to devote time to honoring the 17 students and faculty members killed on Feb. 14. They are Alyssa Alhadeff, Scott Beigel, Martin Duque, Nicholas Dworet, Aaron Feis, Jamie Guttenberg, Chris Hixon, Luke Hoyer, Cara Loughran, Gina Montalto, Joaquin Oliver, Alaina Petty, Meadow Pollack, Helena Ramsey, Alex Schachter, Carmen Schentrup and Peter Wang.
Gun rights advocates
While people across the country march for gun reform, advocates in various cities will also hit the streets in defense of the Second Amendment. There's a common thread running through March for Our Lives protests and pro-Second Amendment demonstrations alike, and that's the need for enhanced school security measures and robust mental health programs. The counter-protesters, though, argue that school safety can be accomplished and gun violence curbed without infringing upon gun owners' rights.
Unlike March for Our Lives, counter-demonstrations are decentralized and (with the exception of one demonstration in Washington) are not sponsored by the National Rifle Association or any other national group.