Starr Carter, a sixteen-year-old black girl, attends a party in her neighborhood, Garden Heights. Starr goes with Kenya, a friend with whom she shares an older half-brother, Seven. Ever since attending Williamson Prep, a primarily white school, Starr feels out of place in the Garden Heights social scene. When Kenya goes off with other friends, Starr runs into her childhood best friend, Khalil Harris, whom she hasn’t seen in a long time. Gunshots from a gang fight interrupt the party, and Khalil offers to take Starr home. While Khalil drives, he explains rapper Tupac Shakur’s idea that “Thug Life” stands for “The Hate U Give Little Infants F---- Everybody.” Soon after, a white police officer with the badge number one-fifteen pulls them over. Khalil questions the motivation for the stop, and One-Fifteen orders him out of the car and searches him. One-Fifteen commands Khalil not to move, and returns to his car. Khalil opens the door to check on Starr. One-Fifteen fatally shoots Khalil.
Starr has nightmares about the death of another childhood friend, Natasha, who died in the crossfire of a gang shooting. At school on Monday, Starr feels tense around Hailey and Chris, her white friend and boyfriend, as memories of Khalil’s death interrupt her thoughts and she realizes they don’t understand. At the urging of her uncle Carlos, a police officer, Starr goes into the police station after school with her mother, Lisa, to testify about Khalil’s shooting. Starr realizes that the officers are asking more questions about whether Khalil was a troublemaker than about the night of the shooting. She worries that justice for Khalil will not be served. At Khalil’s funeral, a lawyer and activist named April Ofrah confirms Starr’s fears when she announces that the police will not pursue legal action against One-Fifteen and invites the attendees to a rally in Khalil’s honor. Starr blames herself for the police’s inaction. King, the head of a local gang called the King Lords, also interrupts the funeral and places a gray bandana on Khalil’s casket, signifying Khalil’s membership in the King Lords. April Ofrah tells Starr to call her if she needs legal representation.
The news that the police won’t prosecute One-Fifteen leads to days of protests in Garden Heights. During this time, Maverick, Starr’s father, explains to her his interpretation of Tupac’s phrase “Thug Life.” He believes that Thug Life describes a system designed against black communities. Only by speaking out can black communities begin to break the cycle. At the Carter family’s grocery store, a teenage member of the King Lords named DeVante begs Maverick, a former King Lord, to help him leave the gang. Maverick agrees. Starr sees DeVante’s request as a chance to help someone in a similar situation as Khalil. A few days later, Maverick gets into an argument with the neighborhood barber, Mr. Lewis. Although the argument is peaceful, two police officers intervene, and when they see Maverick is Starr’s father, they push him to the ground and search him. Between this scary event and pressure from Kenya, Starr decides that she will no longer be silent.
The District Attorney calls Lisa to announce that a grand jury will hear the case against One-Fifteen and asks if Starr will testify. Starr agrees, and April Ofrah decides to represent Starr pro bono, and also find a way to get Starr a television interview. Meanwhile, DeVante tells Starr that Khalil had never been a member of the King Lords and only sold drugs for King to protect his mother, who had stolen money from King. During Starr’s television interview, she decides, against Ms. Ofrah’s advice, to talk about the truth behind Khalil’s drug dealing. Starr’s implication of King enrages him. The night before her grand jury testimony, someone throws a brick and fires a gun into the Carter household. Unsure if the culprits are the King Lords or the police, Starr almost backs out of testifying. However, she ultimately decides that Khalil needs her truth. She testifies before the grand jury.
Almost two months later, the grand jury announces their decision not to indict One-Fifteen. Starr and some of her friends get caught up in the resulting riots. As she tries to avoid the chaos, Starr stumbles upon a protest led by Ms. Ofrah. She offers Starr the megaphone, and Starr leads a chant in front of the protest. The police try to break up the protest with tear gas. Starr and her friends head to the Carter family store to get milk to help heal their eyes. A Molotov cocktail lands in the store, setting it ablaze and trapping them. Maverick arrives just in time to unlock the back door. King arrives to taunt them, proud about getting his revenge. The police arrive, and King, confident that no one will testify against him, claims ignorance. However, the neighbors rally around the Carter family and tell the police that they saw King throw the Molotov cocktail. The police arrest King. Although the grocery store is in ruins, Starr knows that the family will rebuild. She vows to continue fighting for justice on behalf of Khalil and all other black people killed at the hands of police.