Constanze is one of Amanda's closest friends and her roommate. Constanze's technical skills prove particularly advantageous to Amanda, whose machines enable her to work more easily and to have extra fun on the side.
Jasminka is one of Amanda's closest friends and roommates.
—Amanda to Akko, Amanda O'Neill and the Holy Grail
— *Amanda fistbumps Akko*, Luna Nova and the White Dragon
Sharing similar rebellious and brash personalities, Akko easily befriended Amanda during The Enchanted Parade and was one of the students who helped Akko in the absence of Lotte and Sucy. In the television series, their relationship began on a more antagonistic note as they tended to argue. Amanda enjoys teasing Akko, whose often inflated self-confidence and sensitivity to insult make her a perfect target for snark. However, her goal is to provoke Akko rather than hurt her, and she comes to Akko's defense when she is genuinely bullied by others. Like Sucy, she cheers for Akko's successes more than she is amused by her mistakes, particularly when Akko is against their common foe, Diana Cavendish.
By the end of the televison series Amanda and Akko are close friends. Amanda even helps her to stop the bomb by working with all of Akko's other friends.
Not a lot is known about their relationship, but it is implied that they are friends.
Amanda seems to be on good terms with Sucy, and is comfortable with talking to her, such as asking Sucy if she fed Akko "freaky mushrooms" that made her more studious They are both alike in a way, mostly because they use snark more often then not.
Amanda and Diana get along poorly, as in many ways they are opposites. Diana is mature and disciplined, devoting herself to her studies and establishing a great rapport with her teachers. Amanda is immature and rebellious, caring little for her schoolwork and spurning authority. She resents Diana for her lack of humor and for being "too perfect" and haughty about it. On the other hand Diana resents Amanda's lack of seriousness about her work. By the end of the television series they do end up working together to stop the missle, but only because of Akko.
Amanda's relationship with Louis was very antagonistic since their first meeting. Amanda finds it annoying to Louis's arrogant attitude only to be the son of someone of importance as well as his unjustified hatred for witches. Their differences led to a fight with swords in the episode Amanda O'Neill and the Holy Grail. Although Louis broke his promise to lose the duel, Amanda fought to save him from the possessed armor. Louis in turn defended Amanda against the allegations of his father Mr. Blackwell.