Bor the Beggar
- Bor is a human member of the Thieves Guild. Swims-at-Night directs you to him in order to join the guild.
- Lywen is a Bosmer member of the Thieves Guild.
- S'Vanir is a Khajiit and doyen of the Thieves Guild.
The College of Winterhold was added with Heroes of Skyrim.
- Faralda is a member of the College of Winterhold. She was also seen in Skyrim.
- Phinis is a conjuration expert at the College of Winterhold. He was also seen in Skyrim.
- Tolfdir is a member of the College of Winterhold. He was also seen in Skyrim.
- Kianra is an Altmer, and head librarian of the Mages Guild. She is the first member of the guild that you meet.
- Naris is a Dunmer, and the archmage of the Mages Guild.
- Taviah is the conjuration expert in the guild.
The Companions were added with Heroes of Skyrim.
- Aela is a member of the Companions. She was also seen in Skyrim.
- Kodlak is a member of the Companions. He was also seen in Skyrim.
- Ingrid is a human - likely a Nord - and the guildmaster of the Fighters Guild.
Rogthun the Bold
- Rogthun is an Orc member of the Fighters Guild. He is the first member of the guild that you meet.
- Valnia is a human member of the Fighters Guild.
- A Moth Priest who serves as the narrator for the story mode. In the framing story of The Forgotten Hero, he, Isha, and Nagh stole an Elder Scroll, and are hiding from some unknown enemies. He insists that stories can teach them things, and tells them the story of the Forgotten Hero. In The Fall of the Dark Brotherhood, Kellen tells Nagh another story on a different night.
- A Khajiit. In the framing story of The Forgotten Hero, he, Isha, and Kellen stole an Elder Scroll, and alongside Isha he listens to Kellen's tale of the Forgotten Hero. In The Fall of the Dark Brotherhood, he asks Kellen for another story to fall asleep to on a different night.
- A Dunmer friend of Tyr's. Tyr and the hero seek her out because of her knowledge of the Daedra, only to find that she has been kidnapped by cultists. They eventually rescue her and she joins their party.
- A male Argonian smuggler. Tyr and the hero intend to steal his ship, but at the same time Swims-at-Night confronts them, Dominion forces arrive, and he decides to team up with them.
- An Imperial legate and old friend of Tyr's. She joins the hero's party after they defeat a group of Imperial deserters.
- Although only referred to as "The Emperor" and not by name, Emperor Titus Mede II appears: the hero's party comes upon his camp after it has been attacked. Though the Emperor is too injured to lead an attack, the Forgotten Hero wears his armor and takes his place to fight Lord Naarifin.
- A spear-maiden. She, Kellen, and Nagh stole an Elder Scroll. She has little patience for Kellen's stories, but listens to his tale of the Forgotten Hero.
- The main antagonist of The Forgotten Hero; Naarifin is a Thalmor general who currently controls the Imperial City. The hero and Tyr learn that Naarifin intends to bring about a prophecy called The Culling.
- A Dremora in the service of Lord Naarifin. At the beginning of the story he has captured both Tyr and the Forgotten Hero. He wields Goldbrand, which was granted to him by Boethiah.
- A Nord, and a member of the Blades. He was captured by the Dremora, Reive. After initially being forced to fight against the Forgotten Hero, a fellow prisoner, the two decided to work together to fight against their captors.
- Alisanne Dupre is the current Listener of the Dark Brotherhood. She first comes to the hero with instructions to find the traitor to the Brotherhood in Falkreath.
- Andronica is a member of the Dark Brotherhood. Alisanne sent her to kill the two skooma bosses in Bravil, but she went missing and had to be rescued by the hero.
- Arenthil Wethrin is an Altmer from Wayrest and one of the kidnappers of Princess Barynia. The hero confronts him at his house as he holds a gala.
- Astrid is the leader of the Dark Brotherhood in Falkreath. She gives the hero a contract targeting Rathir. She was also seen in Skyrim.
- Babette is a child vampire, the oldest member of the Dark Brotherhood in Falkreath. She first brings along the hero on a contract, and later passes along what she heard about the traitor - and is a potential suspect. She was also seen in Skyrim.
- Balir R'enar is a member of the Dark Brotherhood. He informs the hero of a difficult contract: assassinating the King of Wayrest.
- The Claws Henchman is a member of the Claws, a skooma gang in Bravil. He challenges the hero at the Skooma Den.
- The Claws Kingpin is the leader of the Claws, a skooma gang in Bravil. Andronica was sent to assassinate him.
- The Concerned Citizen is a citizen of Wayrest who points out that the city gates have been left open, and later pleads for the hero to look for her lost "baby", a beloved pig.
- The Eclipse Baroness is the leader of the Eclipse, a skooma gang in Bravil. Andronica was sent to assassinate her.
- Eliras is a member of the Dark Brotherhood in Falkreath. He first brings along the hero on a contract, and later passes along what he heard about the traitor - and is a potential suspect.
- Garnag is an Orc and a member of the Dark Brotherhood. Alisanne sent him to kill the head of the Bravil treasury, but he went missing and had to be rescued by the hero.
- Kastus Thorn is a Dark Brotherhood assassin. The hero faces a choice of confiding in him in the hope that he will extend an invite to join the Brotherhood, or killing him to steal his contract and get the Brotherhood's attention.
- King Barynia is the King of Wayrest. The hero is given a contract to assassinate him.
- The corrupt head of the Wayrest Order of the Hour guard, and the target of Kastus Thorn's contract.
- Princess Barynia is the daughter of the King of Wayrest. After the hero saves her from Dreughside, she offers help later on.
- Rathir is a necromancer posing as the new priest at the Hall of the Dead in Falkreath, and a target of one of the hero's contracts.
- Rathir's Acolyte is a follower of the necromancer Rathir. She doesn't like the hero asking questions about her master, and they fight at the Hall of the Dead in Falkreath.
- The Barkeep is the owner of Cloudy Dregs Inn, who considers the hero to be too nosy.
- The Suspicious Farmer is the target of Babette's contract. Babette suspects that there may be more to her than meets the eye.
- The Eclipse is a member of the Eclipse, a skooma gang in Bravil. He challenges the hero at the Eclipse Hideout.
- The hero finds the Torturer in Bravil, torturing Garnag, and fights him. He may also be encountered later depending on the choices the hero makes.
- The Treasury Guard challenges the hero at the Bravil Treasury during the search for Garnag.
- Uther Nere contacts the Forgotten Hero at the start of The Fall of the Dark Brotherhood, asking for assistance in infiltrating the Dark Brotherhood to avenge his daughter, who allegedly died after joining the Brotherhood.
- Varlyn is a member of the Dark Brotherhood in Falkreath. He first brings along the hero on a contract, and later passes along what he heard about the traitor - and is a potential suspect.
- Zaria is an alchemist at Grave Concoctions in Falkreath, and a former member of Rathir's cult. After the hero defeats her, she offers to provide a disguise if the hero tests a poison she invented. She also appears in Skyrim.
- The "daughter" of the legendary wizard Divayth Fyr, Alfe Fyr helps teleport you to the Clockwork City.
- Almalexia was one of the three members of the Tribunal, alongside Sotha Sil. After losing her godhood, she went insane and killed Sotha Sil. She bears the title "The Temple's Chosen".
- Dagoth Ur was a powerful enemy of the Tribunal who caused them to lose their godhood over 200 years ago. He is fought during a flashback scene taking place in 2E 882 around the time he first awakened and then ambushed and nearly killed the Tribunal during their annual pilgrimage to Red Mountain to renew their divine powers. The event resulted in the Tribunal being cut off from access to the Heart of Lorkhan and prompted Sotha Sil to respond by beginning development of a replacement heart known as the The Mechanical Heart.
- Galyn is the leader of the Brass Fortress Cultists, the populace of Clockwork Apostles who remained in the Clockwork City following Sotha Sil's death.
- The main antagonist of Return to Clockwork City; Mecinar is a former Clockwork Apostle who was cast out of the Clockwork City for experiments involving merging his fellow Acolytes with various beasts, turning them into what Sotha Sil considered abominations. He seeks to absorb the power of the Mechanical Heart, a divine creation of Sotha Sil, and turn himself into a god.
- An Argonian pirate
- The creator of the Clockwork City, who died over 200 years ago.