The film premiered at the Dubai International Film Festival on December 13, 2016, and was released in the United States on December 16, 2016.
Successful advertising executive Howard Inlet (Will Smith) is reduced to a clinically depressed loner after his young daughter’s tragic death. His estranged friends and business partners, Whit Yardshaw (Edward Norton), Claire Wilson (Kate Winslet), and Simon Scott (Michael Peña) fear for Howard’s mental health as well as their company’s future, as Howard’s erratic behavior has cost them numerous high-profile clients and left them on the verge of bankruptcy; as the majority shareholder, Howard has also undermined their efforts to sell the company.
The trio hires a private investigator, Sally Price (Ann Dowd), to acquire evidence that Howard is unfit to run the company, allowing them to take control. Sally intercepts Howard’s letter about abstract concepts of Love, Time and Death, and presents them to Whit, Claire and Simon. They hire a trio of struggling actors – Amy (Keira Knightley), Raffi (Jacob Latimore) and Brigitte (Helen Mirren) – to masquerade as Love, Time, and Death to confront Howard about his letters. Their plan is for Sally to record these encounters and then digitally erase Amy, Raffi and Brigitte to make Howard appear mentally unbalanced, enabling them to sell the company.
In preparation for their roles, Amy, Raffi and Brigitte spend time with Whit, Claire and Simon, who are going through personal problems of their own: Whit is struggling to reconnect with his teenage daughter Allison Yardshaw (Kylie Rogers) after cheating on her mother, leading to a divorce; Claire is looking for sperm donors to conceive a child after neglecting her private life for years; and Simon is battling cancer in secret from his wife and newborn son. Meanwhile, Howard reluctantly begins attending a grief support group and befriends Madeleine (Naomie Harris), who has lost her daughter Olivia to cancer, which led to the end of her marriage. She shares with Howard a note from her husband wishing they could be strangers once again, claiming he’s finally got his wish.
Brigitte, Raffi, and Amy separately approach Howard, but Amy falters, repentant over manipulating Howard. Whit attempts to convince her to return, and also voices his romantic interest in her, but Amy rejects him and only agrees to commit to their plan if Whit commits himself to making amends with his daughter, Allison. He then visits Allison at school and although she refuses to speak to him, he professes his love for her and vows to return every day until she talks to him, touching Allison, who welcomes Whit back into her life. Simon likewise confides with Brigitte about his condition and his fear of death, and she encourages him to share the burden with his family, which Simon ultimately does, being comforted by his wife.
Amy, Raffi and Brigitte confront Howard once again, and he lashes out at them, particularly Amy, externalizing the pain he held inside since his daughter’s death. Amy pointedly tells Howard he owes his daughter’s existence to love and can’t live without it, which inspires Howard to reach out to Madeleine once again. She speaks of the day that Olivia died, in which an old woman at the hospital told her about the “Collateral Beauty”, the acts of selfless kindness that result from tragedies.
The following day, Howard attends a meeting with his company’s board of directors in which Whit, Claire and Simon present the footage of his encounters with Amy, Raffi and Brigitte, without them in the shot. Howard realizes that the video makes him appear mentally unfit to run things and signs over the company, while also voicing his gratitude for all that his friends have done for him, and promising to be there in their times of need. Amy, Raffi and Brigitte later forfeit the payment offered by Claire for their services, and Claire confides with Raffi that she gave up on becoming a mother, but Raffi assures her of her capacities and that she still has time to make her decision, subtly revealing himself to be the entity of “Time.”
Howard visits Madeleine and is invited into her house, where Madeleine persuades him to watch a video of her husband playing with their daughter, who turn out to be Howard and Olivia. Grief had separated Howard from Madeleine, and she agreed to them becoming strangers once again as he had wished. Howard finally acknowledges his daughter’s name and condition, and they make amends and rebuild their relationship. Later, while Howard and Madeleine are walking through the park, Howard notices Amy, Raffi and Brigitte proudly observing them. When Madeleine looks, however, they are gone, while Brigitte, who in reality is the entity “Death”, is shown to be the woman that first told Madeleine about the Collateral Beauty.