Who are all the characters in "The Alchemist"?

Only three characters in The Alchemist are given names.   The boy's name is Santiago.  The old man's name is Melchizedek, and he is the King of Salem.  Santiago's love interest is Fatima, the woman of the desert.

The remaining characters are not given specific names: the gypsy woman, the crystal merchant, the candy seller, the Englishman, the alchemist.   Although not named, each character plays an important role in Santaigo's progress.  In not giving them names, the focus remains on the protagonist and his quest to fulfill his Personal Legend.  Also, by not naming them, they fill the role of Universal Jungian archetypes such as the teacher, the mentor, the father figure, etc. that Santiago would meet along a journey toward fulfillment.

Who are the main characters in The Alchemist?

I have included two links below to give you some more information about the characters in this hilarious play. However, just to get you started, this play by Jonson features various characters that introduce us to a world in which the clever and intelligent prey off the weak and stupid. Subtle is a pseudo-scientist who uses his knowledge to impress the gullible and convince them that he is able to transmute base metals into precious metals. He is aided by Face, who is Subtle's contact man and entices the stupid into Subtle's base to be fleeced. Dol Common is the common mistress of both of these characters and shows herself to be able to impersonate a number of different roles as Subtle's various tricks dictate.

These three central characters are the key tricksters who come up with various stratagems and plots to rid the rich and the foolish of their wealth through their deceit. The remainder of the characters feature those who they prey upon, who are normally shown to suffer from some kind of moral failing that makes them vulnerable to the central characters and their various schemes.