In the early 2000s, the Boston Globe's investigative team, Spotlight, delves into allegations of child abuse within the local Catholic Archdiocese. Under the direction of the new editor, Marty Baron, the team begins to uncover a pattern of sexual abuse by priests and the subsequent cover-up by the Church hierarchy. The reporters, Mike Rezendes, Walter "Robby" Robinson, Sacha Pfeiffer, and Matt Carroll, initially focus on one priest accused of molestation, but their investigation soon reveals a scandal that extends far beyond a single church or priest.

As the team interviews victims and tries to access sealed court documents, they encounter systemic resistance from the community and the Church itself, which goes to great lengths to protect its reputation. The reporters' personal and professional lives are strained by the weight of the story, and they face moral dilemmas over the course of the investigation. With each discovery, they expose the enormity of the scandal and the number of children affected, which escalates the importance of bringing the story to light, while grappling with the potential fallout of their findings on the city of Boston and beyond.