Mark Barden is an American activist and advocate for gun violence prevention, best known as the father of Daniel Barden, a seven-year-old boy killed in the Sandy Hook Elementary School shooting on December 14, 2012, in Newtown, Connecticut. The tragedy profoundly impacted Mark and his wife, Jackie Barden, who lost their youngest son among the 26 victims of the mass shooting. In response, they channeled their grief into action, co-founding Sandy Hook Promise in 2014 alongside other families affected by the event. The organization focuses on preventing gun violence and other forms of violence through programs like 'Say Something,' which educates youth on recognizing warning signs, and broader advocacy for mental health support and commonsense gun laws.

Mark Barden has become a prominent voice in the national conversation on gun control, testifying before Congress, state legislatures, and participating in media appearances to push for legislative reforms such as universal background checks and red flag laws. He has been involved in high-profile events, including the March for Our Lives rally in 2018. Additionally, Mark and his family have faced significant harassment from Sandy Hook conspiracy theorists who falsely claim the shooting was a hoax, leading to legal actions against perpetrators of such misinformation. Despite these challenges, Mark continues to work tirelessly through Sandy Hook Promise, emphasizing education and community intervention to prevent future tragedies.

Prior to the shooting, Mark worked in the financial services industry, but his post-2012 life has been dedicated to advocacy. He resides in Connecticut and remains committed to honoring his son's memory by building safer communities.