Claire is a 60-year-old former World War II combat nurse who lives in the 18th-century American colonies. She serves as a medical healer, utilizing a combination of her 20th-century medical knowledge and local herbal remedies. Following the loss of her home and medical supplies, she prepares for a transatlantic journey to Scotland. She carries deep anxiety about the impending revolution and the safety of her family.

Jamie is an 18th-century Scottish Highlander and former Jacobite managing a homestead in North Carolina. He plans a journey to Scotland to retrieve a printing press, hoping to support the American Revolution through written words rather than frontline combat. He applies his sharp intellect, political awareness, and physical prowess to protect those who depend on him.

Ian is a young relative of Jamie and Claire who spent formative years living among the Mohawk people. He dresses in traditional Mohawk clothing and travels with a part-wolf dog named Rollo. He carries profound guilt following a tragic accident at Fraser's Ridge and hopes a trip back to Scotland will help him find peace.

Brianna is a 20th-century engineer who resides in 1980 Scotland with her husband and young children. She takes a position as a safety inspector at a hydroelectric plant to support her family financially. She relies on inherited letters from the 18th century to maintain a connection with her parents, hoping they survive the historical events she knows are coming.

Roger is a historian and musician living at the ancestral estate of Lallybroch in 1980. He experiences a profound crisis of faith regarding predestination and struggles to secure a sense of purpose after enduring physical trauma in the 18th century. He slowly establishes a new life by accepting a position as an assistant choirmaster and teaching local Gaelic classes.

William is the 19-year-old Earl of Ellesmere serving as a soldier in the British Army. He exhibits eagerness to prove himself in battle and accepts risky intelligence assignments on his way to join military forces in New York. He maintains an idealistic view of warfare that is slowly challenged by the brutal realities he witnesses in the colonies.

Lord John is a British nobleman and former soldier attempting to uncover political intelligence. He uses his extensive social connections in London and the colonies to investigate foreign agents and protect his stepson. He holds lingering, unrequited affections for an old friend, driving him to insert himself into dangerous political situations.

Arch is the elderly former factor of Fraser's Ridge. Following a fatal accident involving his spouse, he makes a chilling vow to delay his revenge until his target has something truly valuable to lose. He travels across the colonies tracking those he holds responsible.

Rachel is a young Quaker woman who assists her brother in providing medical care to wounded individuals. She speaks using traditional plain language and adheres to pacifist beliefs, though she proves capable during dangerous encounters on the road.

Denny is a Quaker doctor with medical training from London. He faces excommunication from his religious community due to his intent to join the Continental army as a surgeon, prioritizing his medical duty over strict pacifism.

Rob is an employee at the Loch Errochty hydroelectric plant in 1980 Scotland. He displays a keen interest in local history and traditional music, eventually socializing with the MacKenzie family outside of work hours.

Percy is a French agent with a complicated past in England. He searches for a missing heir in the American colonies to secure funding for the war effort, using espionage and old connections to gather intelligence.

Fergus is a French-born printer who was adopted into a Scottish family. He prefers a quiet life with his growing family over pursuing rumors about a noble inheritance, actively avoiding foreign agents who seek to involve him in political schemes.

Marsali is a pragmatic woman raising a growing family, including a son with medical needs. She manages domestic responsibilities while supporting her husband's printing business in the tense political climate of the colonies.

Jenny is the matriarch of the Lallybroch estate in Scotland. She cares for her terminally ill husband while managing the household affairs, carrying unresolved bitterness over past family conflicts.

Elder Ian is a Scottish gentleman suffering from late-stage consumption. He wishes to see his family settled before his passing, offering quiet wisdom and acceptance to his son and brother-in-law.

Jem is an eight-year-old boy living in 1980 Scotland. He experiences bullying at school for speaking Gaelic. He possesses specific knowledge about a hidden location mentioned in a centuries-old letter left by his grandfather.

Mandy is a three-year-old girl residing at Lallybroch in 1980. She reports seeing a strange figure lingering around the estate grounds, alerting her parents to an unusual presence.

Laoghaire is a Scottish woman who harbors intense bitterness over a failed past marriage. She relies on alimony payments to support herself and her youngest daughter, complicating attempts at reconciliation.

Buck is a displaced traveler from the past who unexpectedly appears on the Lallybroch estate in 1980. Confused by his modern surroundings, he attempts to understand his situation with the help of familiar faces.

Dottie is a young noblewoman in England. She expresses a sudden desire to travel to the American colonies under the pretense of familial affection, though her uncle suspects ulterior motives.

Hal is a British aristocrat and military man based in London. He coordinates intelligence efforts and worries constantly about his wounded son stationed abroad.

Henry is a British soldier stationed in the American colonies. He suffers from serious combat wounds that require specialized medical attention, prompting intense concern from his family.

Richardson is a British military officer who assigns intelligence missions. His true motives remain opaque, causing concern among those who suspect he may be leading young soldiers into danger.

Rollo is a loyal, part-wolf dog. He accompanies his owner through the American wilderness, providing protection and tracking assistance during dangerous encounters.

Emily is a Mohawk woman living with her new husband and children. She welcomes a peaceful reunion with a figure from her past, offering him closure regarding their shared history.

Murdina is an older woman who worked at Fraser's Ridge. She attempts a covert retrieval of hidden gold, an action that leads to a fatal misunderstanding in the dark.