|Portrayed by||Jaime Ray Newman|
|First appearance||August 24, 2001|
|Last appearance||January 6, 2003|
|Cause/reason||Appeared to Alexis in a dream|
|Cause of death||Murdered by Luis Alcazar in an explosion meant for Sonny Corinthos|
|Residence||Port Charles, New York|
Kristina Cassadine is the daughter of Mikkos Cassadine and Kristen Bergman, an opera singer. She is the sister of Alexis Davis. Her mother was killed by Helena Cassadine, Mikkos' wife. At the behest of Kristin, Alexis hid Kristina in the stables when Helena came to see her mother with the intention of killing her. Alexis came back and saw as Helena slit her mother's throat. When she went back to get her sister, the baby was gone. Mikkos had taken her and left her to be raised by the Carter family in order to protect her from Helena.
A grown-up Kristina set out to look for her sister, Alexis, and hired Angel Sorel Ellis, who Jasper Jacks had also hired to search for Brenda. Angel Sorel Ellis introduced her to Jax and when she realized who she was. After investigating her story, Jax brought her to Port Charles to meet her sister, Alexis. On August 31 2001, Jax approached Alexis and showed that he had found her mother's necklace. The necklace had been stolen by Helena Cassadine when she killed Alexis' mother and later it had been stolen at an auction which took place at the Haunted Star when Alexis tried to recover it. The necklace was composed of two halves, one belonging to Alexis and another that was supposed to belong to Kristina. He also questioned her about the other half of the necklace and about Kristina. Alexis, who had never told anyone about Kristina, refused to talk about it until Jax revealed that Kristina was in fact alive. When they were about to leave to meet Kristina, Alexis received a call from Alan Quartermaine inquiring about a missing Chloe Morgan. Jax and Alexis went to Wyndemere and found Chloe dead (killed by Stavros Cassadine).Alexis stepped in to act as Stefan's lawyer, who had been arrested for Chloe's murder.
Tired of waiting, Kristina put on a man's jacket and hat to disguise herself and went to Luke's. She met Ned Ashton there for the first time. They started to flirt but Ned received a call from Jax informing him about Chloe and asking him to come to the Police Department. Kristina followed Ned to the Police Department, and watched as Alexis broke down in his arms. When Ned left to inform the Quartermaine's of Chloe's death, Kristina approached Alexis and started to introduce herself. Alexis, not knowing who she was and upset about Chloe, interrupted her and told her she did not have time to talk so Kristina left.
Kristina came back to Jax's hotel room and told him that she had met Alexis and that she was a stuffy corporate lawyer, that she no longer wanted to meet her and that she wanted to leave town. Jax informed her about their friend's death and Kristina apologized. When a weeping Alexis came to Jax's hotel room, Kristina hid. Alexis told Jax that the meeting between her and Kristina should wait until she was in better shape. Instead, Kristina came out of her room and introduced herself. They hugged and Alexis later told Kristina the truth about how she was lost to her.
Kristina later changed her name from Carter to Cassadine. Kristina decided to stay in Port Charles and lived with Alexis at the penthouse located next to Sonny's penthouse. She worked as Ned Ashton's assistant at L&B Records. She and Ned got engaged. Alexis later became pregnant with Sonny Corinthos' child and Ned stepped in as the father in an attempt to keep the baby away from Sonny's dangerous business. Feeling betrayed and believing that Ned and Alexis had slept together, she decided to leave town but didn't. Instead, she talked to Alexis and they resolved their differences. She later found a piece of a burned letter which informed her that Sonny was the father of Alexis' baby. She set out to find Sonny to tell him the truth. She called him to meet him at his warehouse but a bomb exploded and she was injured. In the hospital, Alexis' begged her not to say anything and she didn't when Sonny questioned her regarding what she wanted to say to him.
Kristina died on August 6, 2002, when a bomb set by Luis Alcazar was detonated. The bomb was meant for Sonny Corinthos. Alexis named her daughter Kristina in memory of her sister. After baby Kristina was born, dead Kristina appeared in a dream of Alexis', in which dead Kristina's spirit was taking baby Kristina away with her. Days later, Alcazar was pushed from his balcony, and the killer is eventually revealed to be Alexis. Alexis faked DID, saying that her other personality was Kristina, and she was who killed Alcazar. This forced Alexis to don a red wig, and people believed her story for a while.