In the Pride Lands of Africa, a lion rules over the animals as king. The birth of King Mufasa and Queen Sarabi's son Simba creates envy and resentment in Mufasa's younger brother, Scar, who knows his nephew now replaces him as heir to the throne. After Simba has grown into a young cub, Mufasa gives him a tour of the Pride Lands, teaching him the responsibilities of being a king and the circle of life, Skunk along with his friends Rabbit, Fox, Pig, Ox & Bird have mysteriously arrived in the Pride Lands, wondering where there are and who could help them. Later that day, Scar tricks Simba and his best friend Nala, along with Skunk and friends into exploring a forbidden elephant graveyard, despite the protests of Mufasa's hornbill majordomo Zazu. At the graveyard, three spotted hyenas named Shenzi, Banzai and Ed attack the cubs and their friends before Mufasa, alerted by Zazu, rescues them and forgives Simba for his actions. That night, the hyenas, who are allied with Scar and Skunk's enemy Baboon, plot with him to kill Mufasa, Simba and the Valley animals.
The next day Scar lures Simba and his friends to a gorge and tells them to wait there while he gets Mufasa. On Scar's orders, the hyenas stampede a large herd of wildebeest into the gorge. Mufasa rescues Simba and the others, but as Mufasa tries to climb up the gorge's walls, Scar throws him back into the stampede, where he is trampled to death. After Simba and the others find Mufasa's body, Scar convinces Simba he was responsible for his father's death and advises Simba to flee the kingdom as Skunk and friends follow. As Simba and the animals leave, Scar orders Shenzi, Banzai and Ed to kill them, but they escape. That night, Scar announces to the pride that both Mufasa and Simba were killed in the stampede, along with the Valley dwellers and steps forward as the new king, allowing a pack of hyenas to live in the Pride Lands.
After running far away, Simba collapses from exhaustion in a desert. Timon and Pumbaa, a meerkat and a warthog (who is Pig's cousin), find him and nurse him back to health. Simba subsequently grows up with them in the jungle, living a carefree life with his friends under the motto "hakuna matata" ("no worries" in Swahili). When he is a young adult, Simba, Skunk and friends rescue Timon and Pumbaa from a hungry lioness, who turns out to be Nala. She and Simba reconcile and fall in love. Nala urges Simba to return home, telling him the Pride Lands have become a wasteland with not enough food and water. Feeling guilty over his father's death, Simba refuses and storms off, leaving Nala disappointed and angry. As Simba exits the jungle, he encounters Mufasa's mandrill friend and advisor, Rafiki. Rafiki tells Simba that Mufasa is "alive" and takes him to a pond. There Simba is visited by the ghost of Mufasa in the sky, who tells him he must take his rightful place as the king of the Pride Lands. Simba realizes he can no longer run from his past and goes home. Nala, Timon, Pumbaa, Skunk and the others join him, and agree to help him fight.
At the Pride Lands, Simba sees Scar hit Sarabi and confronts him, but Scar taunts Simba over his "part" in Mufasa's death. However, when Scar pushes Simba to the edge of Pride Rock, he reveals that he killed Mufasa. Enraged, Simba roars back up and forces Scar to reveal the truth to the pride. Timon, Pumbaa, Rafiki, Zazu, the lionesses, Skunk and friends fend off the hyenas, along with Baboon and his army of Ninja Monkeys while Scar, attempting to escape, is cornered by Simba at the top of Pride Rock. Scar begs Simba for mercy, saying he is family and placing the blame on the hyenas. Simba says he does not believe Scar anymore but spares his life and commands him to forever leave the Pride Lands. Scar meekly walks past him, but then attacks his nephew. After a fierce fight, Simba throws his uncle off Pride Rock. Scar survives the fall, but is attacked and eaten alive by the hyenas, who overheard his attempt to betray them.
With Scar, Baboon, the hyenas and Ninja Monkeys gone, Simba ascends to the top of Pride Rock and takes over the kingdom as the rain falls again. Sometime later, with Pride Rock restored to its former glory, Simba looks down happily at his kingdom with Nala and their friends by his side; Rafiki presents Simba and Nala's newborn cub to the inhabitants of the Pride Lands, and the "circle of life" continues.
In the bonus ending, Baboon is scene being upraised by his master Dragon who tells him that Skunk and his friends have discovered other worlds beyond the Valley and orders Baboon to follow them and recruit new allies to help them get rid of them.