The STARZ historical fantasy drama Outlander chronicles the escapades of Claire, who gets transported into the 18th century quite by chance when she goes vacationing with her husband in 20th century Scotland. The series transcends various genres from period drama, to fantasy, romance, and adventure.
Claire Fraser might be the central protagonist of the series which revolves around her exploits with the gorgeous Scottish Highlander, Jamie, yet the show has a range of rather fascinating characters, in supporting or secondary capacity. Wherever Claire and Jamie land up, they get into the thick of things within seconds of arriving, making way for several intriguing personalities.
Duke of Sandringham
The despicable duke appeared in the first two seasons of the fantasy drama and was played with alacrity by actor Simon Callow. The duke was shown as a sly, selfish individual, a slippery customer, who would go to any extent to further his own interests.
He was first introduced as someone who could potentially have Jamie's best interests in his heart, but it soon turned out that he didn't have much of a heart in the first place. The duke had a layered personality, but his crafty, conniving nature finally took precedence over everything else, making him duplicitous, wily, and far from likable.
The Comte St. Germain
Another least likable supporting character in season 2 was the Comte St. Germain, who crossed paths with Claire and Jamie almost moments after they arrived in Paris. In the show, the Comte was a dark, scheming personality who tried to kill Claire the first chance he got.
The Comte was killed off at the end of season 2; though his death was perhaps the result of some deceit on the apothecary, Master Raymond's part. But fans felt little grief at the death of a man who seemed evil through and through.
Geillis Duncan
Geillis Duncan, Claire's only fellow time traveler for a long time, was one of the most intriguing characters in Outlander to date. In season 1, Geillis was a supporting character who appeared to have a disastrous ending, being burnt on the stake as a witch. She also sacrificed herself to save Claire, which made her a positive force at the end of the day.
Geillis came back as an antagonist in season 3; it was revealed that she and Dougal McKenzie had managed to deceive the people at the witch-burning and get away safe. Geillis went on to prove herself a severely unhinged individual who cared nothing for human life and practiced dark magic and human sacrifice. Geillis was fascinating, no doubt, but not necessarily likable.
Roger McKenzie
Roger is the distant descendant of Dougal McKenzie and Geillis Duncan. He started out as an adorably goofy young Scots, and then went on to have a much more significant role in seasons 4 and 5, especially when he traveled through time like his wife Brianna and his mother-in-law, Claire.
Roger is generally a good-natured man although there have been times when he has had toxic outbursts, like the time he couldn't handle Briann's rejection of his marriage proposal in season 4. His streak of bad behavior towards her continued after their marriage and even later when he found about her sexual assault, making him a conflicted character at best.
Frank Randall
Frank Randall was probably the most unfortunate character in the series, having been thrust into a whirlwind through no fault of his own, losing the love of his life, and his marriage, in the process.
Frank was genuine in his relationship with Claire; he waited for her to come back when she first disappeared and tried to look for her, agonizing over why or how she could have disappeared without a trace. He also treated Brianna as his own daughter and harbored some unreciprocated feelings for Claire till his death. Even though he did plan to marry again, one might argue that he deserved some marital bliss, after all. Frank was a good, decent man, the victim of fantastic circumstances, and really quite likable.
Murtagh Fitzgibbons
Murtagh is Jamie's godfather and one of the few genuine well-wishers he and Claire have had. Rather like Severus Snape of the Harry Potter franchise, Murtagh too was in love with Jamie's mother and vowed to keep an eye on him.
It was Murtagh who saved Claire when she was on the verge of being raped immediately after landing 200 years in the past, by the fiendish Jack Randall. It was also Murtagh who devoted himself to Jamie and Claire as they went gallivanting around France, and who promised to fight alongside Jamie in the Battle of Culloden, knowing full well that he could die. Murtagh is a fan favorite and by far one of the most likable characters on the show.
Brianna Fraser-McKenzie
Brianna is Jamie and Claire's daughter, who grew up in Boston, unaware of her true parentage and blissfully oblivious of Claire and Frank's troubled marriage.
Brianna is a dedicated daughter to both her fathers. She was, perhaps naturally, resentful of her mother at first, who she thought had never loved Frank, but in time her good sense prevails and she comes to both love and admire her mother for the brave woman she is. Brianna has a charming innocence to her, which is later replaced with a steely determination, much like her mother; she is undoubtedly one of the most beloved characters in the Outlander universe.
Fergus Fraser
The feisty young French lad who became Jamie and Claire's adoptive son for all intents and purposes is another instantly lovable supporting character. Jamie first appointed cheeky young Fergus who was a petty pickpocket at the time, from a brothel in Paris, to do his bidding, and in time, Fergus became family.
Both actors Romann Berrux and César Domboy have done a terrific job portraying the lively, precocious Fergus, although the former perhaps delivered a more memorable performance. Fergus is instantly likable, and a fan favorite.
Jenny Fraser
Jenny or Janet Fraser is Jamie's older sister and one of the strongest female characters on the show. Jenny is outspoken and sometimes brutally honest, and although she is not prone to the display of emotion, she feels things deeply, and either accepts someone wholeheartedly or rejects them completely from her life.
Jenny becomes something of a sister to Claire when she first encounters her in Lallybroch, although she does take some time to warm up to her. Afterward, however, when Claire pops up after a major gap of two decades, Jenny is unable to place her trust in her again. She is a woman of many parts, a survivor of abuse in the hands of Jack Randall, and a pillar of strength in Jamie's life. She can be sharp, but she is also extremely likable, even more so because of the way actress Laura Donnelly plays the role.
Lord John Grey
Lord John Grey is possibly one of the most beloved supporting characters in the series. Lord Grey first appeared as a young boy before the Battle of Culloden; his life was spared by Jamie after which he encountered him again in Ardsmuir Prison.
Lord Grey is inherently good-hearted and has been responsible for coming to Jamie's aid more than once. He is also one of the few gay characters on the show, nurturing feelings for Jamie even though he could never openly acknowledge them. He is also an ideal father figure to young Willie, who is really Jamie's biological son, and quite the most likable of the lot.