Mufasa had a loving relationship with his son. Simba spent much of his time with his father, who taught him how to be a good king, and Simba looked up to his father as his role model. Mufasa loved his son very much, immediately coming to his rescue whenever he is in danger. When Mufasa was killed in the stampede, Simba was heartbroken, believing that it was his own fault. When Mufasa appeared again to Simba years later as a spirit, he encouraged him to return to the Pride Lands, telling him to remember who he is: Mufasa's son, the one true king. Even in death, Simba looks to his father for guidance and his actions are based from what he believes his father would do.
Mufasa and his mate, Sarabi, loved each other very much. When Mufasa was killed in the wildebeest stampede, she was heartbroken. Remaining loyal to her deceased mate, Sarabi boldly states Scar isn't half the great king Mufasa was. In the 2019 remake, Sarabi even went as far as saying that Scar is nothing compared to Mufasa.
As teenagers, Mufasa had a strained relationship with his brother. While Mufasa is aware that his brother doesn't like him, Mufasa still cares and looks after him. Scar harboured some jealousy towards his brother, but he at least still had a begrudging respect for Mufasa and carried out his responsibility as leader of the Lion Guard. However, Scar's jealousy towards his brother took a deadly turn after the venom that he got from a cobra bite intensified his jealousy to deep-seethed hatred.
As adults, Mufasa's strained relationship with his brother worsened. While he did still love and care about Scar, Mufasa was unsure of what to do about his bad attitude. Scar was frequently disrespectful towards Mufasa, which sometimes caused the latter to lose his patience with his younger brother. In the 2019 remake, however, Despite Scar's animosity towards him (and the fact that in the remake states that Scar did indeed challenge him for the throne and Sarabi's affections at one point), Mufasa refused to banish Scar, believing that, as his brother, he still has the right to live in the Pride Lands. Mufasa failed to see Scar's treachery until it was too late, when Scar threw him to his death. Scar's hatred for Mufasa is so deep that he even made it illegal for anyone to mention his name in his presence, particularly in terms of favouritism. Despite being killed by Scar, Mufasa doesn't seem to hold any grudge against his younger brother.
Though he never got a chance to meet his granddaughter because of his death, Mufasa loves his granddaughter very much. Mufasa's spirit watches over and even plays with Kiara through the wind during her presentation. Seeing the connection she and his brother's heir had he knew this would be the perfect way to reunite their feuding prides. Kiara, though not shown conversing with his apparitions, holds profound respect for her grandfather and knew he would've been more merciful to someone in Kovu's position.
Although Mufasa never met his grandson during his lifetime due to him being killed by Scar when Simba was only a cub, Kion held great respect towards Mufasa due to his father often telling him about his grandfather. Kion's respect for Mufasa grows after he's finally able to speak with his grandfather's spirit. Whenever he was in doubt, Kion almost always called upon the spirit of his grandfather for guidance. In return, Mufasa shows his confidence in his grandson, believing that he'll make a great leader of the new Lion Guard. He's always understanding with Kion, and never blamed him for anything, even when Scar returned.
Months later, in Season 3, Kion, now a teenager, defeats Scar, but Ushari bits him in his left eye, leaving him with a scar like his great-uncle's, forcing him to leave for a long journey to the Tree of Life to heal the poison in his body. However, he was unable to control the Roar as he could before, and whenever his scar hurts him, he ended up getting angry, which made the journey more difficult and made him more insecure. It became so bad that ever since the journey started, he stopped talking to his grandpa for months because he was afraid to face him with his scar, especially since Scar was the one who murdered him years ago. Mufasa was saddened and worried about Kion not speaking to him since Scar's defeat, fearing that his grandson has forgotten him like Simba once had. When Kion explains why he didn't talked to him Mufasa assured Kion that he can always confide to him, and that he will always love him, then he admits that he missed him.
Mufasa later watched on proudly as Kion married Rani and became King of the Tree of Life.
Mufasa had a very good friendship with his majordomo. He often turned to Zazu for advice and tasks him with reporting the kingdom's affairs to him or watching over his son, Simba. The duo often cracked jokes with each other, usually at Scar's expense. However, Mufasa wasn't above teasing Zazu, as seen when he uses him as the target for Simba's pouncing lesson. Zazu was saddened when his liege was killed. Under the rule of the unpopular Scar, the hornbill, demoted to being forced to sing for him, recalls how he never had to do such things for Mufasa.
Mufasa had a very close friendship with Rafiki. At his son's presentation, they embraced in a hug and the king entrusts his son in Rafiki's hands. Rafiki was devastated by his old friend's demise. But they collaborated together to get an astray Simba to go back and reclaim his birthright. Rafiki is shown to be able to speak with Mufasa on equal footing; greatly expressing his doubt in the late lion's idea by even stating his head was in the clouds, which was met with howling winds. Still, the mandrill goes through with Mufasa's ploy to get his granddaughter to fall in love for sake of the Pride Lands.
The Outsiders were originally subjects of Mufasa during his reign over the Pride Lands, however after his death, and the supposed death of his son Simba, they swore loyalty to his brother (and secret murderer) Scar. Unlike his son, Mufasa bears absolutely no hatred towards the Outsiders for their loyalty to his evil brother and killer; instead he wishes for them to rejoin the pride and live side-by-side with the pridelanders. Mufasa realizes that so long as the outsiders and Pridelanders remain separate and continue to fight, the circle of life will forever be broken and so he wishes to end the hatred between the two factions so that prosperity could return to the Pride Lands. To do this, he planned on having his granddaughter Kiara and Kovu (Scar’s adopted son and heir) fall in love with each other. Mufasa knew that not only could their respected factions be united through their marriage but would also form the perfect compromise between them as well. This way Kiara would be the regnant queen and Kovu would be the consort king, thus fulfilling the Scar’s wish. Even after the outsiders attempted to assassinate his son and declared war on him and the Pridelanders, Mufasa still bears no hatred for them. His spirit watched over his granddaughter and Kovu’s wedding and the reunification of the prides, happy that balance had returned to his former kingdom.
The hyenas were one of Mufasa's greatest enemies. They would often trespass into the Pride Lands, and Mufasa had to drive them out. When the trio tried to attack Simba, Mufasa defended with great ferocity and threatened them should they ever try again. In spite of this, the hyenas do harbour some form of respect for him. Banzai admits that while they had it rough when Mufasa was ruling, his conditions were better than those of his irresponsible brother Scar.