The Librarians (2014 TV series)

• Rebecca Romijn as Colonel Eve Baird, a former NATO agent whom the Library chose as the "Guardian", tasked with protecting and training the new Librarians and protecting Flynn. In "And Santa's Midnight Run", it's revealed that she was born on Christmas Eve, and her parents named her accordingly. She and Flynn are attracted to each other almost immediately.
• Christian Kane as Jacob Stone, an Oklahoma oil-rigger and genius with an IQ of 190 and an extensive knowledge of languages, archaeology, Native-American culture, art history, conservation, architecture, and more. Fearing disapproval from his family, he has hidden his talents from them, publishing under several pseudonyms and winning worldwide recognition for his expertise. While he initially does not trust Cassandra after her betrayal in "And The Crown of King Arthur", he eventually accepts her as a valued member of the team.
• Lindy Booth as Cassandra Cillian, a mathematician who has uncontrollable auditory and sensory hallucinations linked to memory retrieval, as well as a rare condition called synesthesia. She has a brain tumor, diagnosed in childhood, which causes pain if she thinks hard enough. Because of the extreme pain, Stone teaches her to connect to a peaceful memory during her thoughts. Since her teens, she has been living with the knowledge that this tumor will kill her, unless she risks an extremely dangerous surgery that may take her life and, if she survives, will probably destroy her gift. In season 3, facing death, she has the surgery. The tumor is successfully removed, and she finds her mental abilities are tremendously enhanced, as is her connection with magic.
• John Harlan Kim as Ezekiel Jones, an Australian thief and "master of technologies" he has hacked the London Police's security network, NSA, and numerous other law enforcement agencies. He prefers to rely on his luck and wit, not showing much concern for others until he gets to a point of realizing something important about the current case. In season 3 he reveals to his foster mother—but to no one else—that he does not keep his ill-gotten gains, but uses them to support charities and to help the helpless. He believes that this is why the Library invited him.
• John Larroquette as Jenkins (Galeas/Galahad), the Annex's reluctant, sometimes cantankerous caretaker; he has worked there "for longer than anyone knows" and has extensive knowledge of ancient lore. He is also seen to have a connection to Dulaque, as revealed in "And the Apple of Discord". It is later explained that they are both immortal because of a spell Dulaque cast 1,000 years earlier after the fall of Camelot. He was known during King Arthur's reign as Sir Galahad, as revealed in "And the Loom of Fate". He has also known Morgan le Fay (Alicia Witt) for centuries and considers her to be his archenemy, as he blames her for Arthur's death. In season 4, in “Some Dude Named Jeff,” he confirms that he is the illegitimate son of Lancelot du Lac.

• Noah Wyle as Flynn Carsen, Librarian for the past 10 years, who periodically works alongside the team. Flynn has not retired. The Library has called three additional Librarians to share the burden. Flynn has worked without a Guardian for almost a decade. The Library recruited Colonel Eve Baird to be the new Guardian. At the end of season four, he and Eve became the new immortal tethers for The Library after the previous tethers, Judson and Charlene, passed on to the void.
• Matt Frewer as Dulaque, the mysterious immortal leader of the Serpent Brotherhood, who has a past relationship with Jenkins. He was known during King Arthur's reign as Sir Lancelot du Lac, as revealed in "And The Loom of Fate", and has devoted himself to reversing the events that brought about the fall of Camelot. In the same episode, he is briefly restored to his younger self (Jerry O'Connell), only to be erased from existence by Flynn.
• Lesley-Ann Brandt as Lamia, Dulaque's second-in-command in the Serpent Brotherhood, who serves him faithfully until he betrays and kills her in "And The Loom of Fate". Her name is a reference to the mythical Libyan queen of the same name.
• Jane Curtin as Charlene, the Library’s humorless administrator, who interviewed Flynn for the job of the Librarian. In the final season, it is revealed that she was the first Guardian and that she is immortal. She and Judson performed the tethering ceremony that is one of the season 4 story arcs.
• Bob Newhart as Judson, the first Librarian, who now acts as a mentor to those who take up the mantle. In the third season, it is revealed that he founded the Library in Alexandria during the time of Ancient Egypt after defeating Apep.
• Richard Cox as Prospero, the fictional protagonist of The Tempest, who comes to life seeking to regain his sorcery and conquer the world. During the finale of the second season, ("And The Final Curtain"), he merges with Shakespeare himself, only to be banished back to his original story by the Librarians.
• David S. Lee as Professor Moriarty, the archenemy of Sherlock Holmes, who is summoned by Prospero to assist him. He is eventually returned to his story by Prospero after betraying him in "And The Final Curtain".
• Hayley McLaughlin as Ariel, a real fairy (as opposed to a fictional) who was accidentally written into The Tempest by Shakespeare. She serves Prospero, using her powers to assist him and his followers. In "And The Happily Ever Afters", she manages to disguise herself as a human and contacts Flynn, helping him break her master's control over the other Librarians in exchange for her freedom.
• Beth Riesgraf as the Lady of the Lake, an enigmatic figure that acts as the spokesperson for an intellectual collective that truly comprehends the scientific constructs behind magic and who takes an interest in Cassandra due to her unique abilities. In "And The Final Curtain", she helps Flynn and Eve defeat Prospero in the past by providing them with Arthur's sword, Excalibur.
• Rachel Nichols as Nicole Noone, Flynn's first Guardian (portrayed in the first movie, The Librarian: Quest for the Spear, by Sonya Walger). Flynn thought that she had died, and he is shattered to find her alive, and immortal, in the present. Thrust 500 years into the past, she used magic to prolong her life and spent the next 5 centuries planning what to do when she saw Flynn again.

In Australia, Region 4, the entire series has been released on DVD individually and as a complete series box set.

• The Complete First Season — 13 May 2015[17]
• The Complete Second Season — 23 March 2016[18]
• The Complete Third Season — 15 March 2017[19]
• The Complete Fourth Season — 18 April 2018[20]
• The Complete Series — 6 March 2019[21]

The first two episodes also appeared as a feature film on December 12, 2014 on The CW.[22] The show was acquired by UPtv and premiered on March 13, 2019.[23] The show moved to Ovation in 2019.