Born in New Orleans, Caleb is the only child of Mr. and Mrs. Smallwood. When he was twelve, his father allowed his brother's son, Tyler, to stay with them for a short period of time. A few years later, in 1986, both Mr. Smallwood and his wife died. Later Caleb moved to Fell's Church, at home of his uncles, in early summer, after the "disappearance" of his cousin Tyler, following the fight against Klaus. Suddenly, he finds himself having memories of two conflicting realities (one that was real, and one that was made up of fake memories implanted by the Guardians). The reason he retains his real memories is because he is supernatural (not just a dormant werewolf, but also some kind of spellcaster). He sees newspaper articles depicting each reality as well, and determines from them that Elena and her friends know what has happened and why his memories are so conflicting. Hoping that they also know where Tyler is, Caleb begins doing yard work for aunt Judith, hoping to get closer to Elena so that she will tell him everything.
In an effort to speed up this process, he casts a spell that makes the group jealous of everyone else, hoping they will turn against each other and reveal what they know. He gives Elena, at their first meeting, a rose that has "found" on the porch (probably linked to the spell). He later watches the group during the rescue of Meredith from drowning, at Hot Springs, but Caleb runs away when he is saw by the girl and Matt.
When Elena goes to the cemetery, to visit her parents, she also sees Caleb, who has also lost his parents, and reveals that he was the one who run away to Hot Springs. Stefan shows up and throws Caleb against a tombstone out of envy that he might like Elena. He says that he discovered evidence that Caleb is "evil". Stefan takes Elena to the Caleb's shed, and they see that Caleb had collected many photos and newspapers about them. They detail both realities - of the events that actually happened and everyone's fabricated memories. Stefan and Elena conclude that the Guardians just changed these, but Caleb can see some of them for what they really are because he is supernatural.
Later, Stefan, Meredith and Matt eventually try to confront him in Smallwoods' house, while his aunt and uncle are away, where Caleb reveals his plan. Caleb says that he deduced that the group of friends was behind his contradicting memories and gave Elena the rose, hoping to get closer to her so that he could find out where Tyler went. As Matt stands guard on the first floor, Meredith regretfully informs Caleb that Tyler killed Sue Carson and that they truly don't know what happened to him.
Later, the rose given to Elena by Caleb, will be used to destroy an Original Phantom, that fed the jealousy of the group.
Caleb had shaggy, dark blond hair and blue eyes. He was pale, short and weighed very little, prompting him to use a glamour to make himself seem desirable when approaching Elena.
Caleb is of Hebrew origin, and the meaning is "faith, devotion, whole hearted".
- In the original draft of Smith, Caleb does not fall in the cast of main characters, he was only added later by the ghostwriter.
- Despite being a werewolf, although the gene is inactive, it is unknown as holds, and that entities are, his magical powers. Given that lycanthropy is inherited from the paternal side, it is plausible that the magic has inherited from the maternal side.
- Caleb seems not to be influenced by the werewolf gene, as it does not show any aggressive behavior, as occurs in Tyler's cousin. This is probably due to its magical abilities.
- It is unclear what age has Caleb, but could be bigger than Tyler. Saw that when he was twelve, Tyler visited his relatives, a few years before their death in 1986.
- Caleb's role may have been replaced by Mason Lockwood in the TV series.