Tom Wingfield is the protagonist or main character in the play, he is also the narrator.
"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."
Amanda Wingfield, Tom's mother is the closest thing to an antagonist in the play, she is the clearest villain in Tom's life. She presents him with the greatest conflict, blocking him from having a life of choice and freedom. He must overcome her constant, demanding and nagging behavior to escape from the confining apartment.
Tom must contend with the guilt of leaving his sister Laura behind, in the same way that Mr. Wingfield, his father abandoned the family so many years ago. Tom struggles with the dismal life that he shares with his mother and sister, but her criticism of his every move eventually becomes too much for him to bear.
In the end of the play, Tom must escape to survive, even though he tells the reader that he is haunted by the spectre of his sister, Laura, who he left behind.
The central character, or the protagonist, of Tennessee Williams's The Glass Menagerie is Tom Wingfield. Tom finds himself in conflict with his own character traits at times, so he is sometimes his own antagonist. In addition, Tom is in conflict with tradition and its illusion, as represented by his mother, Amanda, and her values and dreams of a "gentleman caller." Therefore, Amanda is an antagonist to Tom, as she complains that he will not act as "normal people" do, and she tries to force Tom into the role of provider.
In truth, all three characters, Laura, Tom, and Amanda, pay an emotional price because they dwell in illusions. Laura creates an illusory world with her glass menagerie, Tom escapes into the novels that he reads and the movies that he attends, and Amanda retreats to the traditions of her youth and the concept of the gentleman caller who will rescue her daughter and support the family.
AMANDA: Why can't you and your brother be normal people? Fantastic whims and behavior. Preposterous goings on (Scene 6)!
Yet, it is Amanda who blocks Tom from being himself by confining him to the warehouse job, and by making him feel responsible for the care of his sister and mother.
TOM: I'm starting to boil inside. . . Whenever I pick up a shoe, I shudder a little thinking how short life is and what I am doing (Scene 6).
The protagonist Tom is not willing to sacrifice for his family. Yet, he feels guilt as he flees the confinement of his life and the emotional toll of living in a world of illusion.
Although it is a short play with only a few characters, Tom is the protagonist of the play. In the beginning of the play, it is Tom who steps onstage to narrate the story as if it occurred in his past. His life is frustrating because he is the man in the family because his father abandoned them. Although he is the man in the family, he is not allowed to be the father figure. His mother Amanda treats him as a child. She does this throughout the play, but the most obvious one is in the first scene when she criticizes his eating habits as if he's still a child. Amanda imposes a sense of obligation on Tom, even though she is the mother, and her daughter could easily take classes to care for herself in her adulthood. Tom is faced with a sense of duty that he really doesn't deserve. Tom is torn between his past and his future throughout the play because of this sense of duty to help his family and his desire to be independent.