Jeremy, played by Steven R. McQueen, is the younger brother of Elena. When Jeremy is introduced he is seen to be a self-destructive, drug using and angry teenager who is infatuated with Elena's ex-boyfriend Matt Donovan's sister Vicki Donovan. It is insinuated that the pair (Jeremy and Vicki) had a sexual relationship after the death of his parents during the summer and while he still holds feelings for her, she is interested in Tyler Lockwood, the son of the towns Mayor. However, after Vicki's death in episode 1x07 Jeremy is left devastated. His memory of Vicki's death and vampire status was erased by Damon Salvatore on Elena's insistence, though he still feels the loss when Vicki is reported as missing.

Afterwards, Jeremy becomes more involved in his studies, and while researching for a paper in the school library he meets a girl named Anna, who tells him about his ancestor's fascination with Vampires that influenced the town back around the time of the Civil War, beginning his fascination with them. Believing them to be fictional creatures at first, Anna inadvertently reveals her true identity to him when she attacks him in the woods in Order to use him to free her mother and the other vampires from the tomb. While his knowledge isn't apparent at first, once he puts all the pieces together he confronts Anna and asks her to 'turn him'. However she refuses, but begins warming up to the idea only to discover that he only wanted to become a vampire to be with Vicki, whom he believed to be a vampire until her body was discovered by Caroline Forbes.

After a brief falling out, the pair begin a actual relationship a few episodes later with Anna calling Jeremy her "weakness". In the penultimate episode of Season 1, Jeremy is abducted by Elena's birth mother Isobel, a fellow vampire, along with his uncle John Gilbert. However, he is released by Isobel upon Elena promising to swap a devise in return for Jeremy's safety. Accompanying this is Jeremy's discovery that Elena was present at Vicki's death and had his mind wiped of the event, which he finds out more about in detail by reading Elena's diary. After Anna's parents are killed, Anna comes to him with a vial of her blood and says that if he dies with it in his system, he will begin the process of turning into a vampire. Initially refusing, he changes his mind after Anna is murdered by his uncle John after the council organizes a sting operation to take down all of the tomb vampires. His final scenes of the episode involve him drinking Anna's blood and injesting the remainder of Elena's painkillers from her car accident.