In a confined space they call "Room," young Jack lives with his Ma, Joy. They are held captive by a man they refer to as Old Nick, who supplies them with basic necessities but keeps them imprisoned in the small, soundproof shed. As Jack turns five, Joy begins to reveal to him that Room is not the entire world, contrary to what he's been led to believe. She explains that there is a whole world outside and that they need to find a way to escape. Tensions rise as Joy devises a risky plan to break free from their prison, instilling in Jack the courage and understanding necessary for the mission.

The world beyond Room is vast and overwhelming for Jack, who struggles to adjust to the newfound freedom. Joy must navigate her own path to recovery and reintegration with her family while helping Jack acclimate to their new life. Their journey involves dealing with trauma, discovering the kindness of strangers, and rebuilding lost connections. As they face these challenges together, Joy and Jack's bond strengthens, showcasing their resilience and hope in the face of their harrowing ordeal.