Named for the Zulu and Xhosa word for "power," Amandla was born in Los Angeles, California, to Karen Brailsford, a writer, and Tom Stenberg, a businessman. Her mother is African-American and her father is Danish (and of part Inuit-Greenlandic ancestry).
In the summer and fall of 2010, she shot her first feature, Colombiana (2011), an action-thriller starring Zoe Saldana whose character, the avenging assassin Cataleya Restrepo, Amandla plays as a child. In April 2011, Lionsgate announced that Amandla had landed the role of Rue in the screen adaptation of Suzanne Collins' popular young adult series, The Hunger Games (2012). For her heart-breaking performance, Amandla earned an NAACP Image Award nomination for Outstanding Supporting Actress in a Motion Picture. She also won (with Jennifer Lawrence) a Teen Choice Award for Choice Movie Chemistry.
Amandla starred in the recurring role of Macey, the daughter of Captain Frank Irving (Orlando Jones), on season one of Fox's Sleepy Hollow (2013). In the summer of 2015, Amandla played series regular Halle Foster on Mr. Robinson (2015) opposite Craig Robinson. She made her Sundance Film Festival debut with the teen angst drama As You Are (2016) which won a Special Jury prize. Amandla appears in several sequences in the visual album Beyoncé: Lemonade (2016). In March 2016 Fox 2000 won a heated bidding war for Angela Thomas' debut novel, The Hate U Give (2018) with Amandla attached to star. The actor has also nabbed lead roles in the YA adaptation Everything, Everything (2017); the Amma Asante World War II romance, Where Hands Touch (2018); and in the film adaptation of The Darkest Minds (2018) series by Alexandra Bracken.