Claire is a former World War II field nurse and a dedicated surgeon living in the 20th century. After spending three years in the 18th century and leaving her husband behind to protect their unborn child, she maintains a practical exterior that masks deep longing. She possesses remarkable medical skills and a stubborn determination to uncover the truth about the past. Her training allows her to approach supernatural and historical mysteries with a scientific mindset, though her emotional ties to the past remain strong.

Jamie is a Scottish Highlander and the former Laird of Lallybroch who miraculously survives the Battle of Culloden. Marked by his bright red hair and unyielding sense of duty, he lives as a fugitive in a cave to avoid British capture. He bears immense physical and emotional scars from the war and works tirelessly to protect his remaining family. Forced to rely on stealth and the loyalty of his tenants, he endures years of isolation while holding onto the memory of his wife.

Brianna is Claire's intelligent, headstrong daughter who recently learned the truth about her time-traveling origins and her biological father. Raised in Boston, she struggles to reconcile her modern upbringing with the shocking realities of her family's history. She inherits her parents' stubbornness and sharp intellect, utilizing her academic skills to search through historical records for any sign of survival.

Roger is a Scottish historian and academic with a keen interest in the past and a growing affection for Brianna. His research skills provide the crucial link that allows Claire to trace Jamie's movements through the 18th century. He balances his scholarly methodical nature with genuine emotional support for Claire and Brianna as they process life-altering revelations.

Lord John is an English military officer belonging to a prominent aristocratic family. Haunted by the loss of his lover at Culloden, he maintains a strict code of duty while struggling with prejudice against the Scottish prisoners under his command. His interactions with his prisoners challenge his rigid worldview, forcing him to reevaluate his loyalties and personal ethics.

Frank is an English historian and Claire's first husband who raised Brianna as his own daughter. He attempts to maintain a sense of normalcy in their Boston household, though his marriage to Claire suffers from an undeniable emotional distance.

Jenny is Jamie's fiercely protective sister who holds their family estate together during the harsh aftermath of the Jacobite uprising. She possesses a practical, resilient nature and cares deeply for her tenants and loved ones.

Ian is Jenny's husband and Jamie's loyal friend. Despite losing a leg in earlier conflicts, he remains a steadying presence at Lallybroch and works quietly alongside his wife to protect their community.

Young Ian is the adventurous and sometimes reckless nephew of Jamie. He looks up to his uncle immensely and often seeks out excitement, disregarding the dangers of the volatile political climate.

Fergus is an orphaned French youth whom Jamie took under his wing years prior. He displays remarkable loyalty to the Fraser family and uses his quick wits to distract British patrols, sometimes at great personal risk.

Geillis is a fellow time-traveler and Scottish nationalist who shares Claire's interest in herbalism but operates with a much more ruthless ideology. Convinced she can alter history to favor the Scottish throne, she possesses deep knowledge of the standing stones. She views human history as a puzzle to be manipulated, showing little regard for the collateral damage her actions cause.

Joe is Claire's closest colleague and friend in the 20th century. As a Black man in a predominantly white profession, he shares a bond with Claire over their mutual status as outsiders in the medical field.

Lord Melton is an English commander bound by a strict sense of honor. He struggles to balance his military duties with a personal debt he owes to the man who previously saved his brother's life.

Jack Randall is a notorious English captain known for his brutal treatment of Scottish prisoners. His past cruelty casts a long shadow over Jamie and Claire's memories.

Geneva is the beautiful, spoiled daughter of Lord Dunsany. Accustomed to getting her way, she takes an aggressive interest in the Scottish groom assigned to her family's estate.

Mr. Willoughby is a Chinese exile living in Scotland who possesses knowledge of Eastern medicine and acupuncture. He struggles with a severe language barrier and social prejudice in his new environment.

Marsali is a young Scottish woman who asserts her independence by marrying Fergus against the initial wishes of her elders. She possesses a bold personality and gradually learns to adapt to life at sea, taking practical steps to manage her new marriage.

Captain Leonard is a young British naval officer forced to take command during a devastating typhoid outbreak on his ship. He carries out his military duties with rigid adherence to the law, prioritizing his crew's survival and naval regulations over personal gratitude.