- "She's a foreigner, preaching a foreign religion."
- ―Davos Seaworth
Red Priests and Red Priestesses are the clergy in the faith of R'hllor, the Lord of Light. They receive their name for the red clothing they wear. They possess a multitude of ambiguous supernatural abilities, which believed to be the gifts of the Lord himself.
Unlike the clergy of the Faith of the Seven, Red Priests and Priestesses do not take vows of celibacy. Red Priestesses (and possibly priests as well) seemingly also engage in a form of sacred sex.
Known Red Priests
- Melisandre, from Asshai. Called "the Red Woman", also a shadowbinder. Former adviser to Stannis Baratheon and Jon Snow.
- Thoros, from the Free City of Myr. Participated in the Siege of Pyke, fighting with a flaming sword. Now a member of the Brotherhood Without Banners.
- High Priest of Myr.
- A Red Priestess in Volantis.
- A Red Priestess in Meereen.
- Zanrush, a Red Priest active in Meereen.
- Kinvara, High Priestess of the Red Temple of Volantis.
Red Priests have demonstrated a variety of magical abilities. However, it is unknown precisely how these abilities are acquired, and their effectiveness is not always certain. Indeed, sometimes the priests themselves express skepticism regarding magic:
Melisandre can see into the future by staring into flames. She is able to show others these visions, as she did for Stannis after his defeat at the Battle of the Blackwater, completing his faith in her. She also seemed to know that Matthos Seaworth would die by Wildfire, as she foreshadowed his fate to him before the battle. By staring into Arya Stark's eyes, Melisandre was also able to see the eyes of many other people that Arya would "shut forever".
However, these visions can be misinterpreted, or they may not manifest in the way the seer expects. Melisandre claims that she saw a vision of herself witnessing the Bolton banners falling from Winterfell and Jon Snow fighting there. Certain that this meant that Stannis would defeat the Boltons with the help of Jon Snow, she becomes temporarily despondent when both Stannis and Jon are killed, believing that everything she saw in the flames was a lie. The vision is apparently fulfilled later, when the resurrected Jon defeats Ramsay Bolton and Melisandre watches the Bolton banners replaced with those of House Stark.
Upon meeting, Kinvara, Varys expresses his skepticisim about religion in general; he claims that practicioners' mentality of "everything is the Lord's will" is an excuse for lack of genuine spiritual phenomena. Though unfazed, Kinvara counters by revealing events of Varys' childhood that should have been impossible for her to know about; there were no witnesses to the events and those involved were unlikely to have told anyone, yet she was able to describe them in astonishing detail.
Poison ProtectionMaester Cressen attempted to kill Melisandre by slipping poison into a cup of wine. After realizing that the cup is poisoned, Melisandre drank almost the entire cup without fear, completely unaffected by the poison, while Cressen died moments later from a simple sip. The red amulet around her neck lit up and glowed as this happened.
Thoros of Myr showed this ability after Beric Dondarrion fell in combat against Sandor Clegane. By repeatedly chanting "Lord! cast your light upon this man, your servant. Bring him back from death and darkness. His flame has been extinguished, restore it!" Beric was revived alive and well, his wounds healed within seconds of being slain. When Thoros later explains to Melisandre that he had also done this on five other occasions, she is astonished that it happened at all, let alone that it worked six times. Thoros himself insisted that he has no control over this ability, claiming that he's just a lucky drunk who recites the words, and the Lord of Light apparently sees fit to answers his prayers.
In the sixth season, Melisandre employs a different and more elaborate ritual in order to resurrect Jon Snow, involving burning pieces of Jon's hair and repeatedly reciting words: "Zyhys oñoso jehikagon Aeksiot epi, se gis hen syndrorro jemagon. Zyhys perzys stepagon Aeksio Oño jorepi, se morghultas lys qelitsos sikagon. Hen syndrorro, oños. Hen ñuqir, perzys. Hen morghot, glaeson." ("We ask the Lord to shine the light, and take a soul from darkness. We implore the Lord to share their fire and light a candle went out. From darkness, light. From the ashes, fire. From death, life."), in High Valyrian. In spite of the differences in ritual, Melisandre's efforts were a success. 
Some Red Priests can cast magical glamours, illusions which alter a person's appearance in the minds of others. Melisandre uses a powerful glamour which fools all the senses to disguise her true appearance. In the novels, Melisandre uses this trick to switch Mance Rayder's appearance with the Lord of Bones, allowing Mance to avoid execution so she and Jon Snow can send him to Winterfell and rescue who they believe is Arya Stark from House Bolton.
Red Priests possess a much longer lifespan than most human beings; it's possible that their lifespan is indefinite. Red Priests whose lifespan has been extended are not eternally youthful, however, and their bodies will continue to age. Magical and possibly alchemical glamours are used to disguise this aged appearance, so that the ancient Red Priests still seem young and full of vigor. Melisandre is the only Red Priestess thus far confirmed to possess both this long lifespan and the magical powers necessary to disguise it.