Years ago, the Pride Lands was ruled by an unnamed Lion King and Queen, who had two sons. One day, a rouge group of lions attacked the Pride Lands and nearly destroyed it, leading to Prince Askari, the second born son of the monarchy, and his allies to form a powerful force where the kingdom's worthiest would be chosen to stop them. Once the battle was over, Askari and his allies became the Pride Lands' first Lion Guard, a tradition which would be passed down from generation to generation through his nephews, great-nephews, and so-on.
Prince Simba fled the pride after his father, Mufasa, was killed by his uncle Scar, who then took the throne. He returned years later and fought Scar, reclaiming his position as king. Scar's most loyal follower Zira was unwilling to accept this, as she wanted her son Kovu to be the next king as Scar had chosen him for it. When Simba asserted that Scar was never the true king, she attacked him but was defeated. Left with no choice, Simba banished Zira and her family to the Outlands with the other lionesses loyal to Scar, where they became the Outsiders. Years later, the Pride's princess and future Queen, Kiara, was born to Simba and Nala, and later, the future leader of The Lion Guard, Kion, was born.
As the sun rises, Simba teaches his daughter and the pride's future ruler, Kiara, about the pride's kingdom. Kiara's younger brother Kion interrupts, and Simba sends him away so that he can continue to teach Kiara her lesson before she goes to track gazelles with two other female cubs of the pride, Tiifu, and Zuri. Later, Kion becomes the leader of the Lion Guard. Simba takes him into The Lair of the Lion Guard and shows him some of the pride's history: the story of how his great-uncle Scar destroyed his own Lion Guard because they refused to help him kill and overthrow his older brother, Mufasa.
When Kion assembles a Lion Guard that is not made up entirely of lions, Simba reminds his son that there are plenty of good lions in the pride for him to select for the Guard. However, when the members of the Guard prove capable of driving hyenas out of the Pride Lands, both Simba and the pride's queen, Nala, welcome the new Lion Guard.
The prince of Simba's pride, Kion, is the main protagonist of the series and appears in each episode of the show. The other members of the pride serve as supporting characters, and each of them appears in numerous episodes.
Simba falls into a sinkhole along with Bunga. Kion and the rest of the Guard do their best to rescue the pair of them as Nala and Kiara attend an elephant concert. Simba and Kion arrive just as the concert ends.
Kiara, Tiifu and Zuri are going to Urembo Meadows to help Kiara get ready for The Royal Buffalo Wallow. It starts to rain and lionesses are sitting under a tree to stay dry. , the rain clears up and the sun emerges, prompting Tiifu and Zuri to rush into the flowers and roll around in them, gathering the scent. They call for Kiara to join them, but the princess notices an incoming flood. The water surrounds the hill and blocks of their path back to the mainland. Nearby, Ono flies ahead and soon notices the small island. Using his sight, he notices Kiara almost immediately. Soon Ono notices the cubs and warns the guard. The Lion Guard tries to push a tree to the river but the water washes it away. The girls try to move a bolder to the river but that gets washed away too. The Guard and the girls but their ideas together and the girls cross over. Tifu and Zuri feel bad that they didn't help Kiara get ready but she reminds them that there are more important things than how you look. Than Kiara goes over to present the wallow.
Nala gets surrounded by Janja's clan and Kion losses control of the roar. He tries not to use it anymore but Nala says that it's a part of him and he can't stop using it. Later when Makuu's float takes over the Flood Plains the crocs grab the queen and knocks her into the water. Kion uses his roar only at the crocodiles and Nala is saved.
Nala takes Kiara and Kion on a trip to discover "Udugu" a trip that all siblings in the royal family take, while Simba leads the Lion Guard. After their adventures, the royal family rejoices over what it means to have udugu as they watch over the Pride Lands.
Simba invites all the Pride Lands leaders to Mizimu Grove for the Savannah Summit including Makuu trying to place trust in the crocodile. While he asks his son and the guard to watch over things just in the case the others aren't ready to accept Makuu. After thinking through the guard figures out that Makuu is the target of a plot set up by Vuruga Vuruga and Twiga but the crocodile takes great pleasure in the plot and is finally accepted among the other's leaders. With Simba telling Kion he did a good job.
After the guard accidentally wakes up Makuu and his float; Makuu goes to talk to Simba about finding enough water. to get through the rest of the dry season and Kion's whole family attends the Mashindiao between Makuu and Kiburi. But Kiburi (along with Ushari's devious planning) uses the duel to take out Simba, however, thanks to the Lion Guard it was averted. So for Kiburi and his friend's attempt to attack him, Simba banishes them from the Pride Lands and when he hears Makuu forgiving Ono for his earlier mistake. Simba asks the crocodile if this is the new 'crocodile way' and he replies it might be.
The entire pride attends the Ukumbusho where they all happily see the show go off without a hitch until a swarm of bees scares Ma Tembo and her herd into stampeding. Most of the pride notice the bees but stay in place and Simba tries to call out to Ma Tembo in concern but stays with the pride. After the elephants have calmed down the pride watches a new tradition as the Ukumbusho continues.
When Bunga wants to give his uncles the best Christmas ever, Simba and his family, plus Zuri and Tiifu, agree to join in with the celebrations. After rehearsing all night, they are about to give up until Bunga reveals to them how important it is to him, and why. They return and perform The Twelve Ways of Christmas with the other animals.
At Pride Rock, many Pride Landers have gathered for the Kumbuka celebration. As he starts the celebration, Sumu sneaks to the top of Pride Rock and stings Simba on his tail. Although Simba feels the sting, his body reacts almost immediately to the poison, and he collapses while Sumu sneaks away unseen. When everyone rushes to his aid, Simba weakly directs them to his tail, and Rafiki inspects the bloated sting mark. When he reveals it to be that of a scorpion, Kion sends Ono to find it.
But before they can catch him, Sumu enters a hole which leads to the Outlands. Having made sure that the danger has left the Pride Lands, the Guard return to Pride Rock. They find Timon and Pumbaa sobbing uncontrollably, unaware of exactly how bad Simba's condition is.
When they enter Pride Rock, they find Nala and Kiara comforting the barely conscious King, while the Royal Mjuzi and his apprentice use a variety of mixtures that they hope will cure Simba. Suddenly, Rafiki remembers the cure - Volcanic Ash. However, he warns them that it must be recovered by sundown. With the closest volcano being the one in the Outlands, the Lion Guard offer to retrieve it. Rafiki hands Bunga a gourd to place the ash in, but Bunga's cockiness results in the gourd breaking. Rafiki decides to send Makini out with the Guard, and she attaches another gourd to her Bakora Staff. With everyone set, they head out.
When Makini and the rest of the Lion Guard arrive, Kion is dismayed to find his father still on his side, with his mother and sister deeply upset. He gently nudges his father, who weakly acknowledges his son.
Nala explains that, although weak, Simba will be fine. Kion thanks Rafiki, who reminds him that the Lion Guard deserve just as much of the credit. When Timon and Pumbaa start to cry in happiness, Rafiki ushers everyone out, stating that the King needs to rest. As they leave, Kion tells Rafiki that he needs to speak with his father. Rafiki suggests speaking later, so the cub tells him about how they saw Scar, and how he caused the sting in the first place. Worried, Rafiki agrees that, when his father is better, he will need to speak with him.
Kion and Simba talk to Mufasa together about Scar's returning. though the problem is beyond his experience, he is certain that, between his son who has already saved the Pride Lands before from Scar and his grandson who is the leader of the Lion Guard, that they can defeat Scar. He leaves them with the message that "the wisdom is within the Pride Lands", leading both lions to believe that he could be referring to an animal. And Simba knows just who he may be referring to.
After Tiifu and Zuri call the guard for "help" Kiara and Nala claim that the guard is for emergencies only. The girls complain about their fur and how it's too hot. Beshte suggests for them to go to the hot mud pots at the edge of the Pridelands. The girls invited Kiara to come too and they get an escort from Kion and Bunga. While Tiifu and Zuri try to relax Kion and Bunga fool around and have fun. Kiara tries to do both activities until an angry Muhangus emerges from a den, demanding that they keep the noise down. Kion only hears a faint noise suggesting that they leave, but the cubs wish to stay. Soon a huge fire comes Kion, Bunga and Kiara take out the fire while Tiifu and Zuri hide in the mud. Soon the fire spreads all around them and they hide in Muhangus' burrow.
He suggest staying in the cave until the fire is gone but Tiifu tells everyone that she's scared of the dark. Kiara says that they will protect her and stay by her side. Tiifu remains close to her friends with Kion leading the group, though her fear settles in when a strange cry appears in the distance. Suddenly, from out of the ground, a golden mole grabs onto Kion's nose threateningly. Despite his demeanor, his claws tickle Kion's snout, causing him to sneeze and blow him away into Bunga's arms. He continues his fiery approach to the group until he learns that they're not interested in stealing his tunnels, and only wish to return home. He introduces himself as Kuchimba and offers to help them return home after his initial hostility.
Zuri questions if he can get them home without eyes, but Kuchimba explains that he has ears and can smell and feel all the vibrations in the ground, which allow him to get around. They start to follow Kuchimba, and Tiifu asks him if he ever gets scared of the dark. Kuchimba responds by telling her that there's "Nothin’ to Fear Down Here", and how the noises and things she has been seeing are just her imagination. They reach a point where Kuchimba needs to return to his tunnels, much to Tiifu's disappointment. He tells them to take the main tunnel, and they thank the mole for his assistance, with Tiifu remembering his words. Kion comes back to call Kuchimba because they don't know what cave until they here Thurston the zebra coming in. Kion and Kiara decide to track down Muhangus by sent. Soon Kion and Bunga find him wake him up and asks if he can get them out.
When they see daylight Tiifu runs to it but turns back when she hears Thurston panicking and running. She clams him down and the two walk out of the cave together. When the gang comes out the rest of the Lion Guard comes to greet them and tells them that they took out the fire. Kion says it's a long story on how they got in there. Later Thurston goes into another cave and starts to panic again Tiifu comes to help him.
Dhahabu and her herd arrive in the Pride Lands and are greeted by many Pride Landers. They sing "Prance With Me" as Dhahabu makes her way up towards Pride Rock. The Lion guard along with Kiara, Tiifu, and Zuri escort the queen around the Pride Lands. When there's a fire caused by dry lighting Fuli helps Dhahabu over it. Seeing Fuli's actions Dhahabu asks her, Tiifu and Zuri to be her royal guards. Kiara goes to help set up for the celebration while the guard goes on patrol. Soon Reirei's pack sneaks up on Dhahabu and tries to attack her. However, the Lion Guard saves her along with Starehe and Raha. Dhahabu doesn't see her zebra friends save her and asks if Fuli, Tiifu, and Zuri be here guards forever. The girls don't agree and Kion says he'll come up with a plan to get them out of this. The jackals come back again this time joined by a couple of crocodiles from Kiburi's Float. Starehe and Raha once again go to save their friend and Dhahabu finally sees them in action as well as asks for them to be her new guards. That night, Dhahabu agrees to always share their watering hole with the Pride Landers and become friends with them.
Simba is at Mizimu Grove for Makini's Mpana and he welcomes his two great friends Timon and Pumbaa to the stage. The Army of Scar comes to celebration and the Pride Landers and Outlanders begin a battle. Soon Scar reveals himself in front of all the Pride Landers. He tells them his plan to take over the Pride Lands and Simba wipes away the Mark of Evil. The herds start to panic and run while the Lion Guard calms them down. Kion uses the Roar of the Elders on the Outlanders and they blast away. Ma Tembo and Simba have a little chat while the herds start getting mad. Basi asks Kion why he didn't tell them about Scar and Simba says that he was following his orders. The herds start wondering if they should leave the Pride Lands. Simba says that they can tell him in the morning at Pride Rock. That night Kion talks to Mufasa and asks for help. The next morning the herds come to Pride Rock and Kion makes an announcement. They head back to Mizimu Grove and finds Makini's baobab tree which has survived the battle. The herds decided to stay in the Pride Lands and Makini finally plants her tree.
Simba is at Pride Rock with Rafiki watching over the Pride Lands. Years later when the guard is all grown up Kion uses the roar on the Outalnders. Simba claims that it's time to defeat Scar once and for all. Later that night Zazu reports that Hadithi and Shujaa have showed up to help.
Simba asks Kion to lead the herds to the Outlands. Later that night Pride Rock is on fire. With the help from Hadithi and Anga the royal family is free. Soon Scar comes ontop of Pride Rock and explains that they can't stop him. When Scar is gone the herds start to worry. Soon Janja comes and says that he knows how to defeat him. At first Simba doesn't like trusting Janja but Makuu convinces him otherwise. He says that Kion should use his roar on him. The set up the plan and gets some rest.
When Ono can't see they get Ono to Rafiki. Rafiki says that there's nothing he can do about Ono's eye. However for Kion's scar he says to go to the Tree of Life. Ono might get healed too. Anga soon becomes the new Keenest of sight while Ono becomes the smartest. Now with six members on the guard they leave the Pride Lands. Nala and Simba wishes them good luck and is hoping to come back before Kiara's first hunt. The guard leave with Pride Landers wishing them goodbye. Kion talks to Thurston who says that the zebras will protect the Pride Lands while they're gone.
When the Lion Guard comes home after hearing about Zira, Kiara says that Vitani and Kovu have joined their pride. Vitani created her own Lion Guard during the originals' abscence and becomes the new leader, while Kion becomes king of the Tree of Life.