➤ Nadia Petrova: DON'T BE ALARMED! I might be too lazy to fill out my info at the moment but this is still a JACK'O account!

➤ Stefan Salvatore: Katherine fell in love with Stefan when she met him in Mystic Falls in 1864. Although she was also seeing Damon, she had a clear preference for Stefan. She secretly watched over him while running from Klaus, and later admitted she had never once stopped caring about him. Katherine was unwilling to put her love for Stefan above her own survival and when she returned, they became enemies, as Katherine wanted to deliver Elena to Klaus in exchange for her freedom and Stefan was in a relationship with her. Nonetheless, Katherine persisted in her affections for Stefan despite his supposed hatred of her and declared she would wait for him forever if need be. Some time later, Elena tried to kill Katherine in revenge and almost succeeded before Stefan came and saved her. As Katherine's health began to deteriorate after through the loss of The Cure, she developed a friendly but complicated relationship with Stefan. Katherine helped him deal with his PTSD while Stefan in return prevented her from committing suicide. She locked herself and Stefan in the safe where she prompted Stefan to realize he was unable to accept the reality of the loss of Elena and that physical pain was easier to handle. Afterwards, Stefan admitted to Katherine he should move on and they end up sleeping together. Katherine's feelings towards him are stronger than his and her dying wish is for Stefan to find her worthy of redemption.

➤ Damon Salvatore: The relationship between Katherine Pierce and Damon Salvatore has been complicated since their meeting in 1864, when Katherine stayed in their estate and Damon was serving in the Confederate army. Damon fell deeply in love with Katherine, but unbeknownst to him, she'd also been seeing his brother Stefan, sparking the brothers' lifelong rivalry. Their relationship ended when the town began eradicating the vampires. She was then taken away, and Damon and Stefan were shot by their own father while in an attempt to save her, causing the latter's' turning into vampires. Damon since then, has spent the following 150 years obsessed with freeing her from her tomb, only to find out that she was never in it in the first place.

➤ Elijah Mikaelson: The relationship between Katerina Petrova and Elijah Mikaelson, was once sweet and friendly up to the point where Katherine betrayed Elijah for her own freedom and that broke his relationship with his half-brother Klaus. When Elijah found Katherine in the vampire tomb, he compelled her to stay there until he said otherwise. Elijah later revealed that he made Katherine pay for betraying him, by running away from him as he was trying to save her life. She later witnessed his brother Klaus daggering Elijah. In American Gothic, it is revealed that Elijah and Katherine have been sleeping together and was in relationship together, as they both have admitted to being in love with each other, although it is questionable whether Katherine's love for Elijah is genuine or just another ploy to get freedom. However in The Originals, Elijah left Katherine behind in Mystic Falls and went to New Orleans after saying and kissing her goodbye, ending their relationship. Even though he was a hallucination in 500 Years of Solitude, Katherine was happy to see him and had shown to have missed him.

➤ Elena Gilbert: The relationship between Katherine Pierce and Elena Gilbert has been mostly antagonistic throughout the series. When Katherine first came back to Mystic Falls in 2010, she's jealous of Elena for earning the affections of Stefan (and Damon whom she had also loved). Katherine also planned to deliver Elena to Klaus in exchange for his forgiveness for running from him. Katherine, however, has also stated that she's more indifferent to Elena than anything else. She merely saw her as someone who had the same fate as her. After Katherine killed Elena's brother Jeremy, they were each other's only remaining family. After Elena turned her humanity off, she impersonated Katherine for the first time, as it was usually Katherine to impersonate Elena. Katherine later attacked Elena, resulting in Elena giving Katherine the cure, and making her human.