Wedding Band portrays the tragic story of an interracial relationship. The events unfold over three days during the final stages of World War I. The setting is 1918 in South Carolina, where state laws prohibit interracial marriage. Julia, a black woman, is in love with Herman, a white man. They dream of escaping to the North, where they would be free to marry. However, Herman is unable to leave because he needs to repay his mother for a loan she gave him to buy his bakery. As the play begins, Julia and Herman celebrate ten years together. Despite their love, Julia faces the disapproval of her neighbors, which has forced her to relocate multiple times. She is clearly lonely and disheartened. The legal threat of arrest and punishment for interracial couples who marry or live together is real, but the judgment from Julia's black neighbors is equally harmful, highlighting that racism affects both blacks and whites.

In Act I, the audience meets Julia's neighbors. Her landlady, Fanny, is a pretentious black woman who is shown to be shallow and hypocritical. Other tenants, Lula and Mattie, have suffered at the hands of abusive husbands and faced personal tragedies. It becomes evident that all the women in this play have battled against economic hardships and social injustice. In this act, Julia's new neighbors bombard her with questions about her personal life. To quench their curiosity, Julia reveals she has been in love with a man for ten years but cannot marry him because he is white. Her neighbors cannot comprehend why she would choose a white man with no money, and their disapproval is evident as they walk away. Herman then arrives with a boxed wedding cake and a ring to mark their tenth common-law anniversary. The ring is placed on a chain for Julia to wear since they both know she cannot wear it as a wedding ring. Herman gives Julia enough money to purchase a ticket to New York, and she plans to leave in two days. Herman mentions he can settle his debts and join her in a year; in the meantime, Julia can stay with her cousin. They begin to plan their wedding, but Act I concludes with Herman falling ill.

As Act II begins, Herman is suffering from influenza and has collapsed at Julia's residence. The landlady refuses to summon a doctor, fearing legal repercussions for allowing the couple to stay there. She is also worried about the social disgrace that could affect everyone involved, particularly herself. Instead, Herman's sister and mother are called, but his mother insists on waiting until nightfall to move him. Like the landlady, Herman's mother is more concerned with maintaining appearances than ensuring Herman's well-being. The room becomes a battleground for years of racial animosity as Julia and Herman's mother hurl racial slurs at one another. Eventually, Herman is removed amidst numerous accusations and heightened tensions.

The final scene features Julia dressed in her wedding gown. She appears unnaturally enthusiastic, and it is clear she has been drinking wine. She's surrounded by her neighbors, and it is revealed that her neighbor, Mattie, is not legally married because South Carolina does not allow divorce. Although Mattie's first husband was abusive and abandoned her, she remains legally bound to him, preventing her from marrying the father of her child, with whom she has lived for eleven years. At this point, Herman arrives with two tickets to New York. However, Julia cannot overlook the confrontation from the previous day or the lifetime of racial prejudice, so she gives the tickets and her wedding ring to Mattie and her child. As Herman and Julia converse, they reflect on their years of love and closeness, finally resolving the conflicts that had divided them. Unfortunately, Herman is gravely ill and dying. Julia locks Herman's mother out of her home, and the play concludes with Herman dying in Julia's embrace.