Lysa Tully is the younger daughter of Lord Hoster Tully and Lady Minisa Whent. In her youth, she was close to her sister Catelyn and had dreams of falling in love. The two girls practiced kissing with their father's ward, Petyr Baelish, who Lysa would fall in love with. He did not reciprocate. When Brandon Stark became betrothed to Catelyn, Petyr challenged Brandon for her hand and suffered a humiliating defeat. Lysa comforted him afterwards and took care of his wounds, and he took her virginity, thinking she was Catelyn. Lysa became pregnant but her father forced her to abort. Lord Hoster found it difficult to find a suitable marriage for her as she was no longer a virgin. He tried to arrange a marriage with Jaime Lannister, but he was pushed to join the Kingsguard by Cersei. Tywin Lannister offered Tyrion to marry Lysa, but he was rebuffed by Lord Hoster. During Robert's rebellion, Lysa was married to Jon Arryn in the same ceremony as Catelyn's wedding to Eddard. Jon Arryn was already an old man by then, and had married twice, but he had no male heirs and House Tully needed the swords of the Vale. They had a loveless marriage, and Lysa had many miscarriages, but she eventually gave birth to a son, Robert. Jon was made Hand of the King, which brought him to King's Landing, and Lysa's uncle Brynden left Riverrun to serve Lysa's household.
The "Game of Thrones" series has been adapted from the book of the same name, part of the series "A Song of Ice and Fire, written by George R.R. Martin. Lysa Arryn first appears in Game of Thrones #11.
After Jon is mysteriously murdered in King's Landing, Lysa sends a letter to her sister in Winterfell, accusing the Lannisters of murdering her husband. When Catelyn kidnaps Tyrion, she takes him to the Vale of Arryn rather than Winterfell to avoid any pursuers. Catelyn receives a cold reception at the Vale, as Lysa has changed greatly over the years. She has become incredibly paranoid and is overprotective of her son, who she still breastfeeds. Lysa takes Tyrion as her own prisoner and tries to get him to confess to her husband's murder.
Lysa Arryn first appeared in "A Game of Thrones", a novel by George R. R. Martin. Lysa is a recurring character in the series "A Song of Ice and Fire".
Lysa also appeared in the HBO television series, based on "A Song of Ice and Fire", titled "Game of Thrones". She is portrayed by Kate Dickie.