It is shown that Sofia and her mother have a very loving relationship. Miranda is shown to care deeply about her daughter and to not take kindly to people hurting her. Sofia is shown to love her mother more than anyone and has a desire to please her greatly. However, this doesn't stop Sofia from keeping secrets from her. Like the other members of the Royal Family of Enchancia, Miranda is shown to not like it when Sofia does things by herself and only lets her go out under adult supervision. She is also shown to not like her daughter's secrecy and tendency to go off by herself and can normally see through Sofia's attempts to give an answer without giving a straight one. However, she is also shown to have more faith in Sofia and encourages her to be herself.
Sofia and her new father are also shown to have a close and affectionate relationship. He is an instantly liking to his new younger daughter and gave her the Amulet of Avalor. He's also shown to be very protective of her. Sofia is shown to be exasperated by her father's conclusion jumping and stubbornness. However, she loves him anyway and Roland notes he's lucky to have her since she's always looking out for him.
Sofia and her big brother James are shown to have a close bond. This is because the two have a lot in common. James's bond with her is strong to the point where he's very protective of her. However, Sofia is shown to be put off by her brother's immaturity and lack of sense of responsibility. James is shown to be resentful of Sofia's secrecy.
Sofia is not as close to her big sister as she is to her brother. This is because they are so different in temperament. When they first met, Amber took an instant dislike for Sofia due to jealousy. Despite finally bonding, the two remain distant due to their temperament. Amber can't understand Sofia's pragmatism and resents her secrecy despite showing many times that she doesn't deserve Sofia's trust due to showing a shameful amount of disloyalty and rudeness. Sofia is shown to have a tolerance for Amber's dramatics and annoyed by her tendency for hysterics over trivialities. Nevertheless, whenever Sofia is mad at Amber, Amber tries to fix their relationship, so they are glad having the other as a sister.
Sofia was excited to have Amber as a sister after moving to Enchancia Castle. After bonding, despite being two different princesses, Amber became happy to help Sofia on princess things and Sofia turned Amber into an outdoors princess.
Sofia and her Aunt Tilly have a very close relationship to the point where Tilly is the only family member that Sofia is able to completely confide in. Unlike the other members of the Royal Family of Enchancia, Tilly has faith in Sofia's self-sufficiency and lets her do things on her own and gave Sofia the job of being the Storykeeper. She's also the only member of Sofia's family who knows the truth about Sofia's amulet and that Sofia has powers until Elena and the Secret of Avalor, where everyone else is let in on the secret.
Sofia's blind spot is Cedric. Sofia absolutely adores him but Cedric is annoyed by her for the most part and was the only person other than Amber who didn't give her a warm welcome when she came to Enchancia Castle. However, he is touched by the respect she pays him, and trusts her with his magical knowledge.
Sofia and Baileywick hold each other in high esteem due to the fact both are pragmatic and responsible. They also are both from villages.
Sofia and Ruby have been best friends since they were little and both are in the same Buttercup troop, along with Jade.
Sofia and Jade have been friends since they were little and both are in the same Buttercup Troop, along with Ruby. However, their relationship is shown to be shaky. This is because Jade doesn't like Sofia's secrecy and how it makes her go behind her back as shown in "A Tale of Two Teams" and because Sofia is wary of Jade's temper and how it brings out her nasty side.
Vivian was the first person at Royal Prep that Sofia befriended. Vivian was really shy from the start, but Sofia managed to help her overcome her fear of public speaking.
Sofia and Hugo had a rocky start due to the fact they used to dislike each other. Hugo disliked her for being his competition and because of his drop in popularity and Sofia disliked him for his arrogance and macho attitude. In "The Flying Crown", Sofia and Hugo were paired to ride against the Junior Knights in the flying derby championships. When Sofia taught Hugo the meaning of teamwork, she reformed him and they became friends. In "Lord of the Rink", Hugo found himself going through the same thing Sofia went through in "Just One of the Princes", and she understood his feelings. Hugo cares about Sofia to the point where he is quick to come to her rescue, and she respects him for that. They agreed to perform together in an ice-dancing recital and have shown signs of affection for each other.
Sofia and Hugo are also shown to have plenty in common: they both have brown hair (although Hugo's hair color is darker than Sofia's), they're very good flying derby riders and Royal Prep's first flying derby champions, they both don't trust easily and have a habit of keeping secrets and their feelings to themselves, and both have older brothers and are the youngest in their families; due to being the youngest, their relatives seem to barely take them seriously.
Sofia's closest relationship is with her mermaid friend Princess Oona. Sofia and Oona became fast friends due to both being precocious girls with similar domestic troubles and Sofia trusts Oona beyond all her other friends to the point where Oona is the only friend of hers she's able to completely confide in and who knows the truth of Sofia's amulet and about Sofia's powers. Oona is completely loyal to Sofia to the point where she was the only merperson who didn't turn on her after the relevation that she's a human and defended her from bigots like Plank. After Oona was abducted by Sea Monster Cedric, Oona believed that Sofia could rescue her even when Sofia herself began to doubt it when nobody else believed in her.
Sofia became friends with Lucinda the Little Witch after she helped the latter reform and become a good witch. Sofia is devoted to Lucinda to the point where she always defends her from bigots and Lucinda is devoted to Sofia to the point where she's always happy to use her magic to help her. Sofia helps Lucinda show her mother she is a good witch, and then helped her become a Midnight Witch and help her friends get along.
It's unknown how their start was but it's shown that Sofia and Desmond are close. Sofia respects Desmond for his smarts and Desmond respects her for being the only one who didn't make fun of him for his timid nature.
Sofia and Miss Nettle used to be enemies until Sofia helped Miss Nettle get the credit for creating the Nettledrop.
Sofia idolized Carol of the Arrow and her Merry Band of Helping Hands. When she saw them help a horseman, Sofia wanted to meet Carol but was dismayed when she heard Carol voice her dislike for the Royal Family, so she disguised herself as a village girl to meet Carol. Unaware of Sofia's true identity. Carol took an instant liking to Sofia and invited her to join the Merry Band much to Jane's jealousy. After learning of Sofia's true identity, Carol apologized to her, and after Sofia saved Jane and a baby raccoon, Carol welcomed the young princess into the Merry Band.
Sofia's friendship with Hildegard is shaky because, like Amber, Hildegard can be snobbish and speaks her mind too much. Because Hildegard believed it's important to know everything, she tried too hard to impress Sofia by gloating that she knows everything and ruffled Sofia's feathers. When Sofia learned the true reason Hildegard was behaving like that, she told Hildegard that being kind and honest is better than pretending to be someone you're not. However, this didn't stop Hildegard from being insensitive to Sofia in "Dads and Daughters Day", where she unintentionally hurt Sofia's feelings by telling her that King Roland isn't her real father and didn't apologize for it.
Sofia is great friends with Princess Clio and helped her show everyone who she really is. When Sofia learned of Clio's singing talent, she urged her to try out for the schoo play Hello Polly. But Clio told Sofia that she couldn't do that because she and Hildegard do everything together, and Sofia could tell that the only reason for that is because they only did what Hildegard wanted to do. Sofia managed to help Clio realize that it's important that she put her own needs first rather than someone's selfish wants.
Sofia had a rough start with Jane, who was second in command of the Merry Band of Helping Hands. When Carol of the Arrow invited Sofia to join the Merry Band (unaware that she was a princess), Jane became jealous of her and tried to talk Carol out of it only to lose Carol's attention to Sofia. Whenever Sofia had a great idea for a good deed, Jane would sabotage her ideas and even wound up exposing Sofia's true identity. Jane furiously told the Merry Band to forget about Sofia and rescue the raccoon only to feel guilty when Sofia took off. When Jane tried to rescue the raccoon, she wound up going down the river, and Sofia arrived and came to her rescue. Jane gratefully thanked Sofia for saving her and admitted her jealousy and that she made Sofia's good deeds go wrong. When Sofia was accepted into the Merry Band, Jane happily welcomed her in.
Sofia had a bumpy start with Oona's big sister. Cora took an instant shine to her but turned against her after Sofia revealed that she's a human. Things got worse after Oona was kidnapped by Sea Monster Cedric. Their bond took a positive turn when they saved Oona together.
At first, Sofia and Sir Jaxon were enemies due to the fact she was trying to help Sir Oliver get the Ice Fire Shield at first. Despite this, Sofia respected Jaxon for being more honorable than Sir Oliver. They became friends after Sofia saved his life and Jaxon revealed Oliver's deception.
Sofia and Plank had an extremely negetive start. Plank took an instant shine to Sofia but turned against her after she revealed that she's a human. Things got worse after Oona was abducted: When Sofia told the colony about Oona's abduction by a sea monster, Plank refused to believe her and accused her family of kidnapping Oona. Plank however was forced to accept in the end that Sofia was telling the truth after Oona was rescued.
At first, Sofia was afraid of Willawing the dragon and her dragon friends because they were setting fires all over Brazendell, unaware that Sir Oliver was responsible. But when Sofia saved Sir Jaxon from the flood Sir Oliver caused, Willawing revealed her true colors to Sofia, and she thought Sofia was so adorable that she just picked up and embraced Sofia and tickled her chin. Sofia and Willawing became friends after Willawing and Jaxon revealed Sir Oliver's deception.
Sofia and Wendell were enemies when Wendell kidnapped Minimus to get something he wanted. Sofia, Amber, and James reunited with him when they were all sent to Camp Wilderwood. Sofia remarked that Wendell may deserve a second chance...or a tenth chance. Sofia was surprised but pleased that James and Wendell were getting along. In the end, Sofia and Wendell became friends after winning a race with the Junior Knights summer camp.
Sofia and Mandy first met when they first came to Camp Wilderwood, and they became fast friends. Although Sofia introduced Amber to Mandy, Mandy was more interested in Sofia than Amber. Sofia suggested Mandy and Amber be camp buddies during a race with the Junior Knights summer camp but wound up not having a buddy of her own. That's when Mandy and Amber invited Sofia to join them.
Sofia and Slickwell got along great at first. But after Baileywick suddenly became clumsy and Slickwell urged him to retire, Sofia began to lose her respect for the man and after she discovered he was the reason Baileywick became clumsy, Sofia instantly developed an extreme dislike for him and scornfully exposed him to her parents.
Squires Vaughan and Vance became Sofia's new flying derby rivals in "The Flying Crown". Sofia dislikes them for the same reason she used to dislike Hugo. They didn't complain about racing with a little girl, but Vaughan remarked that he and Vance would win the Flying Crown like they did every year. Sofia didn't have respect for them due to their arrogance and rudeness. Vaughan and Vance may have been unaware that Prince Hugo helped Sofia pass them during the race as they wondered how she was able to outpace them.
Sofia and Hornpipe had a falling out when he refused to believe her about Oona's abduction. When Sofia told him and her family about Oona's abduction and Queen Emmaline's threat to sink the Floating Palace, Hornpipe refused to believe her and even accused her of making it up out of spite. When it was confirmed Sofia was right, he didn't apologize to her and they have been enemies ever since.
Sofia and Princess Ivy have been enemies ever since the latter came to Enchancia. Ivy came to Enchancia when Amber jealously stole Sofia's amulet and tried to use it to summon a Disney Princess. When Ivy met Sofia, she offered to be best friends with her, but confused by the amulet summoning Ivy, Sofia told Amber that her amulet only summons Princesses when there's an emergency and then sends them back. When Ivy heard this, she used a butterfly to steal the amulet and tried to destroy it much to Sofia's horror and chagrin. Ivy tried to hit Sofia with a memory-erasing dragonfly, but Amber let herself take the hit to save her younger sister. As a result, Ivy went back to her deserted island, and thanks to her dragonflies, Sofia is the only one who remembers her.
At first, Sofia liked Crispy because she thought he was cute. But after his true colors as a crook were revealed to her she scornfully exposed him to Vivian. Crispy made the mistake of underestimating Sofia, who became his undoing.
Sofia and Mamanu have been enemies ever since Sofia foiled Mamanu's plot to steal the Emerald Key of Hakalo.
Prince Roderick of Borrea became Sofia's new princely enemy when they first met. Unlike Prince Hugo, who used to be villainous himself, Roderick was bad enough to actually threaten to hurt Sofia.
Sofia and Sir Oliver were allies at first due to the fact she tried to help him get the Ice Fire Shield at first. Despite this, Sofia had no respect for Oliver due to his arrogance and rudeness. They became enemies after Sir Jaxon revealed Oliver's deception.