- "For the Watch."
- ―Olly after stabbing Jon Snow
Olly is a recurring character in the fourth, fifth and sixth seasons. He is played by guest star Brenock O'Connor and first appears in "Breaker of Chains". He was originally a farm boy at the Gift, but flees to the Night's Watch after his village is attacked by wildlings.
When Olly and his father are on their way home for dinner, their village is attacked by a group of wildlings. When his father is killed by Ygritte, his mother tells him to hide. He flees, and she is killed by Styr. Olly hides under a cart, but is caught by the Thenn warg. The warg brings him to Styr, who holds a blade to his throat. Styr tells Olly that he is going to eat his dead parents, and orders him to tell the men of the Night's Watch at Castle Black in an attempt to draw them out into the open. He then releases Olly, who reaches Castle Black and informs the men of the approaching wildlings.
Olly stays at Castle Black, living amongst the brothers of the Night's Watch and wearing the black clothes of the Night's Watch. He later trains with them for the upcoming fight against the wildlings. Olly brags to the brothers about his archery skills, though only Grenn says he believes him, as well as promising to take him hunting soon. Battle of Castle Black, Olly is assigned to work the wooden lift system. As the battle rages on Samwell Tarly urges him to pick up a weapon and defend himself. Olly then spots Ygritte preparing to kill Jon Snow. Before she can shoot Jon, Olly uses a bow to kill Ygritte with an arrow through the heart, avenging his father in the process. After the arrival of Stannis Baratheon and his forces, Olly is among the black brothers that attend when the fallen brothers are burned in Castle Black's courtyard.
Olly remains at Castle Black and spars with Jon Snow in the training yard, alongside other new recruits. He has little experience with a sword and shield, but Jon does his best to teach Olly how to be a proper swordsman. Olly abruptly stops sparring when Melisandre arrives to fetch Jon. Later, Olly is present when Mance Rayder is executed by Stannis Baratheon for refusing to bend the knee.
Jon later names Olly as his personal steward, grooming him for command as Jeor Mormont once did for him. He is present at Jon's meeting with Stannis Baratheon and Davos Seaworth, in which Jon points out, while looking at Olly, that many of his black brothers do not like the wildlings. Later, Davos asks Olly to recite part of the Night's Watch oath in order to persuade Jon to rally the Night's Watch to Stannis's side in the upcoming battle for the North. Olly is later at a meeting of Night's Watch where Janos Slynt refuses to man and repair Greyguard, a ruined castle on the Wall. Jon orders Slynt to be brought outside and orders Olly to bring him Longclaw. Olly gives Jon his sword and witnesses Slynt's execution.
However, Olly's trust in Jon begins to sour after Jon makes the suggestion of allowing the wildlings to pass through the Wall and become subjects of the Seven Kingdoms or even members of the Night's Watch so as to avoid them falling into the coming White Walker army. First Steward Bowen Marsh points out what the wildlings did to Olly's family and friends in the Gift while in Mance Rayder's army. Later, in Jon's office, Olly asks if Jon means to lure the wildlings into a trap, but Jon denies it, reminding Olly that despite the losses they have suffered at the wildlings' hands, they will need all the help they can get if the Night's Watch is to stand a chance against the White Walkers.
Later, Olly visits Sam in his rooms, ostensibly to offer him some food. However, he wants to ask Sam why Jon would want to join forces with the Wildlings, particularly Tormund, who led the raid in which his parents were killed. Sam reassures Olly that Jon knows what he is doing, and that unless he is successful, neither the Night's Watch nor Westeros stands a chance against the White Walkers. Sam explains this is a hard choice Jon had to make, however unpopular, and then then tells him not to worry, as Jon always comes back.
When Jon Snow returns from Hardhome with thousands of wildlings and lets them in through the Wall, Olly is among the many black brothers who look at the wildlings and even their Lord Commander with disgust. When Jon smiles at Olly, the boy goes away angrily.
Olly is sent to Jon's room to let him know that a Wildling knows where his uncle Benjen is. Jon quickly rushes out of the room, across the courtyard and past a group of Night's Watchmen, only to find a sign with the word "Traitor" scrawled upon it. Several Night's Watchmen mutiny against Jon and stab him, bringing him to his knees, and Olly approaches. Jon whispers Olly's name as a plea for mercy. With tears in his eyes, Olly finishes Jon off by stabbing him through the chest, ending the mutiny and leaving his Lord Commander dead in the snow. 
Olly is present in the dining room of Castle Black when Thorne announces Jon's murder at their hands and gives his justification to sway most of the Watch to his side. He witnesses Thorne issue Davos Seaworth and the brothers loyal to Jon his ultimatum to surrender or die.
|Season Four appearances|
|Two Swords||The Lion and the Rose||Breaker of Chains||Oathkeeper||First of His Name|
|The Laws of Gods and Men||Mockingbird||The Mountain and the Viper||The Watchers on the Wall||The Children|
|Season Five appearances|
|The Wars to Come||The House of Black and White||High Sparrow||Sons of the Harpy||Kill the Boy|
|Unbowed, Unbent, Unbroken||The Gift||Hardhome||The Dance of Dragons||Mother’s Mercy|
|Season Six appearances|
|The Red Woman||Home||Oathbreaker||Book of the Stranger||Season 6, Episode 5|
|Season 6, Episode 6||Season 6, Episode 7||Season 6, Episode 8||Season 6, Episode 9||Season 6, Episode 10|
Behind the scenes
Olly was invented for the TV series, but was originally just supposed to appear for one episode as a means for the garrison at Castle Black to learn that Tormund's group of wildlings are raiding villages in the Gift, to try to draw men away from Castle Black. Writer's assistant Dave Hill (who wrote the "Histories & Lore" animated featurettes on the Blu rays for Seasons 2, 3, and 4) then suggested to Benioff and Weiss that Olly should then join the Night's Watch, because he has nowhere else to go. Hill also suggested that it would make dramatic sense if they make Olly the one who kills Ygritte during the Battle of Castle Black (in the books, it wasn't clear who fired the arrow that killed her, though Jon briefly believed that he had). Benioff and Weiss were so impressed with this suggestion that they promoted Hill to write an episode script in Season 5, where he gained more prominence by becoming Jon Snow's personal steward and later dealing the final blow to Jon in the mutiny at Castle Black.
In the books
In the A Song of Ice and Fire novels, there is no character by this name. However, Jon takes another young black brother known as Satin, a former male whore from Oldtown, under his wing, as his own steward.
In the novels, it wasn't clear who shot the arrow that mortally wounded Ygritte. When Jon Snow found her, for a frantic moment he feared that he was the one who shot her - but when he checked the arrow in her he recognized that the fletching on it was different from the arrows he was using. Ygritte dies in Jon Snow's arms, with essentially the same dialogue as in the TV series. Afterwards, Jon decides that he'd rather not know which of his sworn brothers fired the arrow that killed Ygritte, so he makes no attempt to check.
Three quarters of the inhabitants of Mole's Town flee to Castle Black after Jon Snow warns them of the wildling raiding parties. The blacksmith Donal Noye, who takes command in the absence of other officers, allows them to stay on condition that they take part in the defense of the castle during the battle. Olly in the TV series, however, is not from Mole's Town but a smaller village in its vicinity (Jon explained that the wildlings were progressively attacking bigger settlements to try to draw out Castle Black's garrison, working their way up to Mole's Town). It is unknown if any people from other villages come to seek refuge at the castle. After the attack of the Thenns is repelled, many of the villagers think that the worst is behind and return to the village. A few residents from Mole's Town decide to stay rather than risk going back to the weakly defended lands to the south, among them: Zei the whore, Hareth (aka Horse) the stablehand and three young orphans (nine, eight and five years old) whose father was killed on the steps. Olly is perhaps loosely based on those orphans, though it is not mentioned whether they take active part in the battle and what becomes of them later. Zei is sent by Jon to the village to recruit the villagers, but she does not return. After the battle is over, Hareth joins the Watch.
In the television series, Olly is the only mutineer who is in tears while stabbing Jon, which is a nod to the novel where Bowen Marsh and the mutineers attacked Jon with tears in their eyes.