Cersei Lannister's soulmate was Eddard Stark. The pair were never married, and Cersei's son eventually ordered the beheading of Eddard. Cersei married Ned's closest friend, and Ned came to love his wife.
Lyanna Stark's soulmate was Rhaegar Targaryen, though it was widely believed to have been Robert Baratheon. The pair had one child, after marrying secretly.
Jaime Lannister's soulmate was Elia Martell, though the pair exchanged few words before Elia's untimely death, which was ordered by Jaime's father, Tywin Lannister, as well as the deaths of Elia's two young children.
Oberyn Martell's soulmate was an Essosian man who passed away of Greyscale when Oberyn was young. The pair never married.
Tywin Lannister's soulmate was his first cousin, Joanna Lannister, whom he wed. The couple had three children before Joanna's death giving birth to the third.
Brandon Stark's soulmate was Ashara Dayne. The pair did not marry, but did have one stillborn daughter, whose death caused Ashara to commit suicide.
Rhaella Targaryen's soulmate was a blacksmith in King's Landing, who never knew she was his soulmate. Rhaella watched over him her entire life, until her death giving birth to her and her husband, her brother, Aerys's, third healthy child.
Aerys Targaryen's soulmate was a simple farmer girl from the Stormlands, whom Aerys drove mad from torture, after discovering his soulmate's status.
Arianne Martell's soulmate was Viserys Targaryen, whom she met when the pair were both young. They never saw one another again, as Viserys's family was overthrown.
Myrcella Baratheon (Lannister)'s soulmate was the youngest son of Doran Martell, Trystane Martell. The pair were both murdered by the Sand Snakes before their eighteenth birthdays.
Arya Stark's soulmate was Tommen Baratheon (Lannister). The pair only met a couple of times when they were young, and Tommen committed suicide before Arya's eighteenth birthday.
Renly Baratheon's soulmate was Loras Tyrell. The pair never married, but visited one another in private until Renly's murder.
Sansa Stark's soulmate was Tyrion Lannister. The pair were married were once, before the marriage was declared void after Tyrion's arrest of treason, and after the marriage had not been consummated.
Bran Stark's soulmate was Meera Reed, whom he met when he was young.
Rickon Stark's soulmate was Shireen Baratheon, whom he never met, due to her death by burning alive as a sacrificial offering when she was young.
Robb Stark's soulmate was Yara Greyjoy, whom he never met before his assassination at the hands of his family's enemies.
Theon Greyjoy's soulmate was Margaery Tyrell, whom he never met before she burned alive in the explosion at Baelor the Blessed's Temple.
Joffrey Baratheon (Lannister)'s soulmate was a common miner boy from the bottom of King's Landing. Joffrey met him only once, and both knew who the other was. The next day when Joffrey sent soldiers out to have the boy killed, he had disappeared from the Crownlands.
Jon Snow's soulmate was his paternal aunt, Daenerys Targaryen. The pair married in their late teens.
Varys's soulmate was a lord from Essos, who died years before Varys came into the service of the Crown of Westeros.
Aemon Targaryen's soulmate was the almost-twenty-years-his-junior Olenna Redwyne. Both had the knowledge of who their soulmate was, but after Olenna made the decision to seduce Luthor Tyrell, as opposed to wedding her soulmate, as she saw more of an opportunity, Aemon joined the northern Night's Watch, where he stayed until his death.
Gregor Clegane's soulmate was the prostitute, Shae. Shae chose Tyrion Lannister over Gregor, and died at his hands.
Khal Drogo's soulmate was the son of a minor khal. The two were childhood friends, until the young boy's premature death.
Ramsay Bolton's soulmate was the wildling, Ygritte. The pair never meant, and neither knew the other's identity, though Ramsay had the suspicion that his was a wildling due to the location of the cuts and bruises on his skin, which reminded him of a wildling style he had studied when he was younger. And, Ygritte felt that hers was the spoiled son of a southern lord, due to how little scars appeared on her body.
Melisandre's soulmate was Sandor Clegane, whom she met only once, and had no desire to pursue a relationship with.
Gendry Waters's soulmate was Missandei, a slave girl from Essos. The pair met after Daenerys Targaryen conquered Westeros, and married soon after.
Brienne of Tarth's soulmate was the Queen's guardsmen Daario Naharis. The pair met on several occasions, but each was clouded by the love they held for another, and exchanged only a few meaningful words. Brienne for Jaime Lannister, and Daario for Daenerys Targaryen.
Davos Seaworth's soulmate was Ellaria Sand. The pair met on occasion when they were older, both having children from past relationships. Ultimately, the two could not comprehend the other's lifestyle, and remained acquaintances the remainder of their lives.
Catelyn Tully's soulmate was Ilyn Payne. The two had never before spoken even a word to each other when Ilyn was ordered to behead Catelyn's husband, Eddard Stark. The two had never met when Catelyn was assassinated during the War of Five Kings, and Ilyn was later murdered by Catelyn's daughter, Arya Stark.
Robert Baratheon's soulmate was the almost thirty-years-his-senior Genevieve Lannister. The two had met when Genevieve was long since married to a Frey Lord, and Genevieve never told a soul, especially since her niece went on to marry the young king. Robert drunkenly spouted the lie to his friend, Eddard Stark, who died with the secret.
Hodor's soulmate was Selyse Baratheon. The two, as happen with many soulmate cases, never met their entire lives. Hodor died protecting Bran Stark, and Selyse committed suicide after her daughter was burned alive by her husband.
Petyr Baelish's soulmate was Mance Rayder. The two never met, and Mance perished first at the Battle of Hardhome.
Stannis Baratheon's soulmate was Tyene Sand. The two never met, and neither was particularly interested in the other, anyway. Stannis was murdered first by Brienne of Tarth.
Tormund Giantsbane's soulmate was Ros. The two never met, but Ros always knew her soulmate was a warrior by how often she received scratches, where she knew her soulmate had piercing wounds. Tormund, in turn, frequently noted the dark bruises on his body, though mostly near the genitalia, and came to the conclusion that his soulmate was a prostitute, more than likely in Westeros. Tormund felt the pain of Ros's death more so than a normal person who had never met their soulmate would.
Samwell Tarly's soulmate was Grey Worm. By the time the two met, Sam was already in a committed relationship with the wildling, Gilly, and a close advisor of King Jon. Grey Worm, in turn, was seeing Missandei until she met her soulmate, and was committed to Queen Daenerys, as her head of security and the Unsullied. Sam and Grey Worm developed a closer relationship after Gilly's death, when they were elders, but it was only ever friendly.
Barristan Selmy's soulmate was Minisa Whent, who was later Minisa Tully. The two met when Barristan traveled to Riverrun with King Aerys's court, and exchanged brief pleasantries. It was during this exchange that Barristan realized the soon-to-be Lady of Riverrun, who was madly in love with Hoster Tully, was his soulmate. Minisa had no knowledge of this, and never learned it throughout her entire life, while Barristan savored every glimpse he received of her over the next twenty years leading up to her death. He then protected Minisa's three surviving children in whatever way he could.
Lyanna Mormont's soulmate was Jojen Reed. The pair met when they were very young at a celebration in Winterfell. Jojen was more than five years Lyanna's senior, so the two were never particularly close. There was talk of a betrothal before the War of Five King, but after members of House Reed (including Jojen) went missing, these negotiations ceased. Lyanna is said to have been confined to bed for weeks, uncontrollably ill after Jojen's death during the War of Five Kings.
Gilly's soulmate was the eldest brother of Yara and Theon Greyjoy. This brother died at a young age. Gilly, not understanding these feelings, had an ache in her chest, that could be described as something like heartburn, for two days after her soulmate's death, when she was seven years old. Gilly was punished for this behavior, as many believed her to be sick, and that she would infect others around her, since no one, except Craster, understood what was happening.
Podrick Payne's soulmate was Talisa Maegyr. The two had glimpsed one another a scarce number of times by the time of Talisa's murder, and neither ever knew who their soulmate had been. Talisa had married before her death, and Podrick was said to be irritable for almost five days after the Red Wedding, and to have had an extremely irritating rash.
Lysa Tully, later Lysa Arryn's soulmate was Jorah Mormont. The two briefly met during the wedding dinner of Jorah's liege lord, Eddard Stark, to Lysa's sister, Catelyn Tully. Both immediately knew they were the other's soulmate, and both were immediately horrified. Jorah could not believe his soulmate was so ugly, and Lysa could not believe he was of such low status compared to her. There was a mutually unspoken agreement that neither of them mention this ever again, and after this Lysa became the Lady of the Vale, and Jorah was exiled to Essos. Jorah is said to have felt only a twinge, for about half a week, after his soulmate's murder.
Walder Frey's soulmate was Craster. The two never met, but were both extremely malevolent. Walder had tens of wives, and hundreds of descendants, while Craster was a wildling who married his daughters to procreate with them. After Craster's death, Walder is said to have been bedridden for days, overreacting to a sharp pain in his lungs that probably only lasted for just over twenty four hours.
Beric Dondarrion's soulmate was the wildling, Osha. The two never met, but both did work for Catelyn Stark during at least one point in their lives. Beric was known to be overly affectionate towards his soul mark, often wearing tunics that showed it off on his arm. Though he never outright searched for his soulmate, Beric had hoped he would find his soulmate while traveling with Lady Stoneheart. Unfortunately for Beric, Osha was protecting Rickon Stark, and was killed by Ramsay Snow. Beric is said to have suffered from a stab wound that appeared on the left side of his body, the same way that Osha was murdered, and been on bed rest for at least a week and a half, despite attempts to leave.
Brynden Tully, or the Blackfish's, soulmate was Lynora Hill. Lynora was a couple of years older than Brynden, and the bastard half-sister of Lady Joanna Lannister. Lynora and Brynden fell in love when Brynden was sixteen, and were planning to wed in secret, despite Lynora's status. Lynora was burned alive by the Mad King Aerys II, two weeks before the wedding was to take place.