Some time after Simba becomes ruler of the Pridelands, his wife, Nala, gives birth to a daughter who they name Kiara. Simba's advisor, the mandrill Rafiki, gathers the animals of the Pridelands to herald the ceremony celebrating Kiara's birth. Mufasa's spirit watches over the ceremony from above.
Months later, Kiara grows older and wanders into the Outlands, evading her supervisors, Timon and Pumbaa. In the Outlands, she meets another lion cub named Kovu. After the two escape from several crocodiles, they are confronted by Simba and Kovu's mother, Zira, the ruler of the Outlanders, who had been exiled by Simba in the past due to their loyalties to Simba's deceased uncle Scar. Zira dares Simba to punish Kovu for trespassing, but he relents and forces the two to leave before returning Kiara to the Pridelands. Afterwards, he scolds Kiara for disobeying him. Meanwhile, Zira schemes to use Kovu's friendship with Kiara to exact revenge against Simba.
Years later, Kiara becomes an adult and sets out on her first solo hunt, but is dismayed to learn that Simba had sent Timon and Pumbaa to watch over her once more. Furious, she strays further from Pride Rock to continue hunting. However, Zira sends her offspring, Nuka and Vitani, to set fire to the plains where Kiara is hunting. Kiara passes out and is rescued by Kovu. Simba arrives and reluctantly thanks Kovu for rescuing his daughter and allows him to live at Pride Rock, but forces him to sleep outside the den. The following morning, Kovu notices Simba alone and plans to attack him, but is interrupted by Kiara, who requests that he help teach her to hunt. Simba, hesitant to trust Kovu, is advised by Nala to give him a chance. At the same time, Kovu begins to doubt his mission to kill Simba and plans to leave the Pridelands, but Rafiki invites him to a musical journey with Kiara. During the evening, Kovu and Kiara fall in love. Simba, finally opening up to Kovu, allows him to sleep in the den.
The following day, Simba takes Kovu out for a walk and tells him the true story of Scar. However, Simba is ambushed by Zira's pride, who claim that Kovu had set him up. In the ensuing confrontation, Nuka is killed, but Simba manages to escape. Zira blames Kovu for Nuka's death and scars his face before driving him off. He returns to the Pridelands, but is exiled by Simba, who also orders Kiara confined to Pride Rock. However, she escapes and reunites with Kovu. The two return to the Pridelands to unite the two prides, and they discover that Zira has waged war against the Pridelands. Kovu and Kiara put a stop to the battle and convince Simba to stop the conflict. He agrees and reconciles with Kiara. The other Outlanders side with Simba's pride, but an unconvinced Zira makes a final attempt to attack Simba, only to be tackled off a nearby cliff by Kiara. As Zira dangles from the cliffside, Kiara offers to save her, but Zira rejects help and falls to her death.
Simba allows the Outlanders to return to the Pridelands, and Kovu marries Kiara. He joins Kiara and her parents at the top of Pride Rock to celebrate. Mufasa's spirit watches over Pride Rock and congratulates his son for his decision.