21 Grams is a 2003 American psychological drama film directed by Alejandro González Iñárritu from a screenplay by Guillermo Arriaga, based on a story by Arriaga and Iñárritu. The film stars Sean Penn, Naomi Watts, Charlotte Gainsbourg, Danny Huston and Benicio Del Toro. The second part of Arriaga's and Iñárritu's "Trilogy of Death", preceded by Amores perros (2000) and followed by Babel (2006), 21 Grams interweaves several plot lines in a nonlinear arrangement.

Alejandro González Iñárritu is a Mexican filmmaker. He is primarily known for making modern psychological drama films about the human condition. His projects have garnered critical acclaim and numerous accolades including four Academy Awards with a Special Achievement Award, three Golden Globe Awards, three BAFTA Awards, two Directors Guild of America Awards. His most notable films include Amores perros (2000), 21 Grams (2003), Babel (2006), Biutiful (2010), Birdman (2014), The Revenant (2015), and Bardo (2022).