Alfonso Calderón Atienzar[a] (born October 10, 2001)[2][3] is a Spanish-American student activist against gun violence.

[6][7] He is a survivor of the Stoneman Douglas High School shooting and a founding member of the Never Again MSD movement.

[6][8][7] Calderon was born in a Spanish town outside Madrid called Alcobendas, and he has been living in the United States since 2008.

[9][4] Calderon criticized lawmakers for failing to enact sensible gun laws as well as screenings to keep mentally ill people from being able to buy "military grade weapons",[8] and he criticized the National Rifle Association (NRA)[6] and their spokesperson Dana Loesch for encouraging gun proliferation[10] as well as politicians funded by the NRA.

[12][13] He views his advocacy as more than merely protecting Parkland students but as an effort to save human lives in general.