Tom, Amanda and Laura are the main characters of the play.
Laura is an important character, as is Amanda, but they are not the protagonist. Tom Wingfield is the protagonist; the story belongs to him.

"The protagonist of a literary work is the main character, who must change in some way during the course of the events, even if the change is entirely internal. Tom is clearly the protagonist of The Glass Menagerie. Although he is not heroic and will probably never triumph over his obstacles, he does take action by the end of the play."

It is, in essence, his story and tells of what he wants out of life and how he reacts to life. Tom Wingfield is the protagonist; the story belongs to him. The drama focuses on Tom's internal and external conflicts during the time he is trapped in the dingy St. Louis apartment during the Great Depression, torn between his dreams and his sense of responsibility for his mother, and especially, for his sister. Tom's restlessness, resentment, and his misery color every scene in which he appears, which is almost every scene in the play. Tom's conflict is developed through his relationships with Laura and Amanda. The fourth character, Jim O'Connor, acts as a functional character; it is his appearance in the Wingfields' home that acts as the catalyst to push Tom into a final break with his mother.
Tom is actually two characters in the play: Tom the narrator, who presents the story in the retrospective point of view years later after having left home, and Tom the young man who stars in his own narrator's memory. The contrast between the two formulates a major theme in the play: Tom left St. Louis and his sister behind, but he never escaped. There was no escaping his past and his own identity. Tom's final speech in the conclusion of the drama makes this clear in a very poignant way.
Amanda Wingfield, Tom's mother is the closest thing to