Dr. Jekyll: This is the elderly gentleman at the centre of the story who struggles with the dual nature of his personality. Although very kind and friendly to his friends, Dr. Jekyll has a dark side, which he chooses to express in the person of Mr. Hyde. Although he valiantly tries to keep Mr. Hyde away, eventually the dark side of his personality wins out, threatening his life.

Mr. Utterson: This man is the main character of the story. Utterson is a lawyer but also a personal friend to nearly all of the other characters, and helps solve the case of Dr. Jekyll and Mr. Hyde. The story is told from his perspective and the reader soon realizes that he’s a good-natured man. Utterson is described as shy, with a rugged countenance.

Mr. Enfield: Enfield is the best friend of Utterson. He goes on weekly Sunday afternoon walks through the town with him. One Sunday, Enfield tells Utterson about Mr. Hyde and the strange house in which he lives.

Dr. Lanyon: Lanyon is an elderly doctor who helps Utterson to solve the case when he describes the letter given to him by Jekyll. Lanyon is the one who witnesses Jekyll’s transformation into Hyde and he writes a letter to Utterson, before dying, to explain Jekyll's transformation.

After this initial presentation of the main characters of the novel, we will try to analyse their relationships with vice and evil, morality and friendship.

Richard Enfield and Mr. Utterson complement each other's limitations. Enfield is not as sober as Mr. Utterson is; he is a model of experience. Enfield is a distant kinsman of Utterson and also his best friend, so he contacts with Mr Hyde's evilness because of Utterson's friendship with Dr. Jekyll. He is not presented as a man full of vice, neither as an evil one. Instead, he is a "well-known man" respected by the society as a man full of virtues. He represents, with Utterson and Lanyon, the moral side of the society.

Mr.Utterson is very sober. He works as a lawyer and so, he has access to Jekyll's will. He is respected and he is shown as a gentleman (he is moral). As the best friend and the confident of Jekyll, he is strongly related to the vice and evilness of Mr.Hyde but he remains virtuous and moral all the novel long. His morality makes him say to Jekyll that he has not to establish contact anymore with Hyde.

Dr. Lanyon was a friend of Dr.Jekyll, and he is still a good friend of Utterson. While Utterson and Enfield complement each other's limitations, as we have said, Jekyll and Lanyon reveal each other's emptiness. He breaks his friendship with Jekyll because he sees Hyde's transformation into Jekyll. Because of his morality, he tries to make Jekyll renounce to continue his experiments but Jekyll refuses and so, they are not friends anymore. He is related to vice and evil as he is in contact with Mr.Hyde.

Dr.Jekyll is seen by the society as a moral man, but one day he becomes tired of being so moral and he "creates" Mr. Hyde, which is his alter ego. His experiments would not be seen as "moral" in his society and Hyde is, definitely, an immoral, wicked and full of vice man. As Henry Jekyll, is one of the best friends Utterson has and he was Lanyon's friend. As the story goes on, he leaves his friends apart in order to spend his whole time with his experiments. As Edward Hyde, he has no friends and, moreover, he frightens everybody. Both Hyde and Jekyll die.