Simba is an African lion who lives in the Great Circle of Life (song "Circle of Life"). He is the son of King Mufasa and Queen Sarabi and is next in line for the crown. As a cub he was excited to be the king of Pride Rock (song "I Just Can't Wait to be King"). When he and his best friend Nala were very young, they both snuck into an elephant graveyard which Simba's uncle, Scar, told him about and his father and father's assistant, Zazu, forbid him to visit. The two cubs are almost eaten by hyenas and are rescued by Mufasa. He is the main protagonist of The Lion King and a deuteragonist of The Lion King II: Simba's Pride and The Lion King 1/2.
Mufasa then tells Zazu to take Nala home and has a talk with Simba, scolding about his disobedience. Simba then tells his father, "I just wanted to be brave like you." His father then tells him that he's only brave when he has to be. The two then play together and Simba makes a remark that they'll always be friends and always be together. Mufasa tells him to look at the sky and that the great kings of the past and are always watching out for them. Afterwards Scar sent a trap so Mufasa would die in a stampede and sent Simba away, making him believe it was all his fault. Simba joined up with Timon and Pumbaa and grew up in their forest.
Once Simba turned a full adult, he didn't want to fix his past, he left it behind and he enjoyed his new life with Timon and Pumbaa. Later on, he was found by the lioness, Nala(his best friend in childhood), and was convinced he needed to back and take his place as king. While being defensive, he left Nala after they reunited. His father, and Rafiki talked sense into him and persuaded Simba to go back and challenge Scar.
He got back, finding himself telling what truly happenmed to his father. After the confession, Simba was able to have Scar submit and tell the real truth! Then the fight began! Scar was defeated and Simba took his place as king.
The adult Simba is voiced by Matthew Broderick and child one voiced by Jonathan Taylor Thomas.