In the West African kingdom of Dahomey in 1823, General Nanisca, leader of the all-female regiment of warriors, the Agojie, liberates Dahomean women who were abducted by slavers from the Oyo Empire. This provokes King Ghezo of Dahomey to prepare for an all-out war with the Oyo. Nanisca begins to train a new generation of warriors to join the Agojie to protect the kingdom. Among these warriors is Nawi, a strong-willed girl who was offered by her father to the king after refusing to marry men who would beat her. Nawi befriends Izogie, a veteran Agojie. She also reveals to Nanisca that she is adopted and shows a scar on her left shoulder, shocking Nanisca.Portuguese slave traders led by Santo Ferreira and accompanied by the half-Dahomean Malik arrive as part of an alliance with the Oyo, led by General Oba Ade. Nawi encounters Malik while the latter is bathing, and the two become friends. Shortly after graduating from training to become a full-fledged Agojie, Nawi sneaks off to speak with Malik and learns that the Oyo are planning to attack. She reports this to Nanisca, who tells her off for her recklessness. Amidst a heated argument between the two, Nanisca reveals that in her youth, she was captured by Oba, raped, and impregnated. After giving birth to a daughter, Nanisca embedded a shark tooth in her left shoulder before giving her away. Nanisca helps Nawi extract the tooth, confirming that she is her biological daughter.Nanisca leads the Agojie in an attack on the Oyo. The attack is successful, but Oba escapes and Nawi, Fumbe and Izogie are captured. With Nawi's advice, Fumbe escapes and reports the others' fate to Nanisca. Ghezo prepares to bestow the title of Woman King, his partner and equal in ruling Dahomey, upon Nanisca, but refuses to authorise a rescue mission for the captive Agojie. Meanwhile, Izogie is killed in an escape attempt and Malik buys Nawi to protect her. Nanisca defies orders and sets out with a group of like-minded warriors to rescue the captives. The chaos allows Nawi to escape and rejoin Nanisca. Malik frees several other slaves who drown Ferreira, and Nanisca kills Oba in single combat. The triumphant Agojie return to Dahomey, where Ghezo privately and briefly admonishes Nanisca for disobeying him, before crowning her the Woman King. After the festivities, Nanisca and Nawi privately acknowledge their familial relationship.