The Chief Ancestors of Motunui and the Ancestor Ensemble recount the tale of how, over a thousand years ago, Maui, a shapeshifter and demigod, stole the heart of the goddess Te Fiti, the mother island ("In the Beginning..."). While trying to escape with the Heart, Maui was attacked by Te Kā, a demon of earth and fire. In their struggle, the Heart was lost to the sea. Fearing Te Kā's violent wrath, the Villagers of Motunui stopped voyaging, a defeated Maui disappeared, and the Ocean guarded the Heart of Te Fiti.

In the present, the Ocean entrusts the Heart to Moana on the island of Motunui ("Tulou Tagaloa"). Despite Moana's strong connection to the Ocean, her parents, Chief Tui and Sina, view it as dangerous and prevent her from venturing out beyond the reef. They advise Moana to embrace her future role as the chief of the village, and the other Villagers join in to encourage Moana to find happiness on the island ("Where You Are - Parts 1 and 2").

When the Villagers lament their blackened crops and the shortage of fish, Moana suggests fishing beyond the reef, but her father forbids it. Moana contemplates breaking the rules and voyaging out to sea ("How Far I'll Go"). Her friends, Pua and Hei Hei, try to stop her, but she remains steadfast. Together, the three push out to sea, but a large wave quickly capsizes their canoe.

Gramma Tala sees this failed expedition and decides to reveal the truth of their ancestors' voyaging past to Moana ("We Know the Way"). Soon, Gramma Tala grows weak, and in her last moments, urges Moana to draw courage from her inner voice, revealing that it is her destiny to return the Heart of Te Fiti ("Where You Are - Reprise"). After Gramma Tala's passing, an emboldened Moana resolves to fulfill her destiny and save Motunui ("How Far I'll Go - Reprise").

Moana lands on an island and meets the arrogant, yet charming, Maui ("You're Welcome"). She convinces him to help her restore the Heart of Te Fiti. However, Maui insists that they first find his magical fishhook, which allows him to shapeshift. To do this, they journey into Lalotai, the Realm of Monsters ("Warrior Face - Parts 1-3"). Here, they find Tamatoa, the giant, egotistical crab who collects valuable objects - including Maui's hook.

In Tamatoa's lair, Moana acts as a distraction while Maui finds his hook ("Shiny - Parts 1 and 2"). Maui tries to shapeshift and save them both from Tamatoa's clutches, but he fails to harness the hook's powers. To escape, Moana cleverly tricks Tamatoa into pursuing a piece of glowing algae that resembles the Heart of Te Fiti ("Shiny - Playoff").

Distraught over his failure to shapeshift, Maui loses confidence, but the ever-resilient Moana refuses to give up ("Warrior Face - Reprise / Logo Te Pate"). A revitalized Maui then agrees to teach Moana the ancient skills of wayfinding to help them in their mission.

As Moana and Maui finally approach Te Kā, they are met by treacherous seas. When Moana refuses to back down, a powerful wave cracks Maui's hook. Wanting to avoid permanent damage to the hook, Maui leaves Moana to finish the quest alone. Gramma Tala appears and reminds Moana of who she is and where she comes from ("Song of the Ancestors").

With her confidence restored, Moana finally faces Te Kā. Maui returns to help, but Te Kā destroys his hook. Listening to her inner voice, Moana suddenly has a realization about Te Kā and lets the monster approach. Face to face with
Te Kā, Moana places the Heart into Te Kā's chest ("Know Who You Are"). Te Kā transforms into the goddess Te Fiti and restores Maui's hook ("Te Fiti Restored" / "Tulou Tagaloa - Reprise").

Moana returns home to a revived Motunui. Once more, the Villagers of Motunui assume their identity as voyagers, now with Moana as their master wayfinder ("We Know the Way - Finale").