Jonathan Flynn Harker is a fictional character and one of the main protagonists of Bram Stoker's 1897 Gothic horror novel Dracula. His journey to Transylvania and encounter with the vampire Count Dracula and his Brides at Castle Dracula constitutes the dramatic opening scenes in the novel and most of the film adaptations. Stoker appropriated the surname from his friend Joseph Cunningham Harker (1855–1920), a set designer at the Lyceum Theatre and father of actor William Gordon Harker (1885–1967) as well as great-grandfather of actress Polly Adams, whose actress-daughters Susannah Harker and Caroline Harker adopted the Harker surname for their stage names.
Harker is a recently admitted solicitor from Exeter, England, who is deputed by his employer, Mr. Hawkins, of Exeter, to act as an estate agent for a foreign client named Count Dracula who wishes to move to London, England. Harker discovers in Carfax, near Purfleet, Essex, a dwelling which suits the client's requirements and travels to Transylvania by train in order to consult with him about it.
At Bistritz, Harker takes a coach to the Borgo Pass where at midnight another coach drawn by four black horses, waits to take him to Castle Dracula high in the Carpathian Mountains. At the castle Harker is greeted by the mysterious and ominous Count Dracula and finalizes the property transaction. Soon, however Harker realizes he has been made a prisoner by his host who is revealed as a vampire. Harker also has a dangerous encounter with the three seductive Brides of Dracula, whose designs on him are only thwarted by the intervention of the Count. He promises to give Harker to them after his business deal is concluded and gives them a "wiggling bag" (highly presumed by Harker to be a human child) to appease them. Dracula leaves for England and abandons Jonathan in the castle as a meal for his vampire brides as he promised them.
Jonathan manages to escape, finding refuge at a convent. He suffers a mental breakdown after his experiences with the vampires; his fiancée, Mina Murray, comes to nurse him back to health with the nuns' help and marries him there. He returns home to England and later sees Dracula in London. After learning Dracula killed Lucy Westonra, he joins Abraham Van Helsing, Seward, Holmwood, and Morris. His clerical skills prove very useful for collecting information and for tracking down Dracula's London lairs by means of paperwork. He vows to destroy Dracula and, if he could, to send "his soul forever and ever to burning to hell[..]!" even if it be at the cost of his own soul. When confronted with Mina's curse, however, he is unsure how to react; Mina asks the others in the group to kill her if the need comes. While Harker says he would, in the privacy of his journal says that if it is necessary, that he would become a vampire himself out of his love for her. However, Harker manages to avoid that because along with Van Helsing and the others he manages to hunt down and destroy Dracula. At the book's climax, he pries open Dracula's coffin mere moments before sunset and slashes open Dracula's throat with a kukri knife, possibly decapitating him, while Quincey Morris stabs him in the heart with a Bowie knife.
In a note following the end of the novel, it is revealed that seven years have passed. Jonathan and Mina have a son whom they have named after all four members of the party, but call Quincey, after Quincey Morris. Noting Quincey Harker's birthday is the day Quincey Morris died fighting Dracula, Mina likes to think that some of Morris's spirit is in their son. Jonathan Harker eventually visits Dracula's castle along with his wife and son and their surviving friends to reminisce. He returns home with his wife and son and is told by Van Helsing that one day his son will learn the whole story.