The entire play takes place in the same house in a neighborhood known as Clybourne Park. The first act takes place during a Saturday afternoon in 1959. Bev and Russ Stoller are packing up their house as they prepare to move to a new home closer to Russ’s job. Their maid, Francine, has come to help them pack, but is clearly unhappy to be working during the weekend. Following the suicide of their son, Kenneth, a veteran of the Korean War accused of murdering civilians, Bev and Russ’s marriage has been deteriorating. Russ is clearly depressed, and Bev has no tools to cope with her husband’s depression. She has asked a local pastor, Jim, to stop by, and Jim tries to talk to Russ about his emotions—to no avail.
Midway through the first act, Bev and Russ’s neighbors arrive, Karl Linder and his wife Betsy. Although Karl initially hides his reason for visiting, he reveals he has discovered that the people who have bought the Stoller’s house are a black family. He has offered them money not to move into the neighborhood, which they have declined, and so Karl has now decided to convince the Stollers to halt the sale of their house. A violent argument ensues after the conversation turns to their son Kenneth, with Russ and Bev expressing indignation at being called on to protect a community that was unkind and unwelcoming to their son.
Francine’s husband, Albert, arrives to take Francine home, but he is roped into helping move a footlocker of Kenneth’s, and then into a conversation around whether he and Francine would hypothetically like to move into a white neighborhood like Clybourne Park. Russ eventually drives Karl and Betsy out of the house. Then Jim, Francine, and Albert all leave as well. Bev and Russ are left onstage where they consider their future in the leisurely suburbs.
The second act takes place during a Saturday afternoon in 2009. Lena and Kevin, a black couple from the Clybourne Park neighborhood, have made plans to meet with Lindsey and Steve, the white couple that just purchased Lena and Kevin’s. Both couples bring lawyers to the meeting. Lena and Kevin’s lawyer is named Tom, while Lindsey and Steve’s lawyer is named Kathy. Together, the couples and their lawyers try to work through a proposed set of restrictions on what can and cannot be remodeled, put together by a neighborhood committee dedicated to preserving the historic character of the neighborhood’s homes.
However, the conversation never gets on track. What begins with small talk spawns an argument over the neighborhood’s historical value versus its new economic value. Kevin and Lena are worried that Lindsey and Steve are the beginning of a wave of gentrification that will price them and other black families out of Clybourne Park, while Lindsey and Steve feel attacked for simply trying to buy and renovate a home.
The discussion goes completely off the rails when, prompted by an off-color joke Steve tells, the group begins telling increasingly offensive jokes, which nearly culminates in a physical altercation. Throughout the second act, a contractor named Dan has been digging in the backyard. Dan comes into the house several times to ask questions about a trunk he found buried in the yard. The trunk, it is revealed, belonged to Kenneth, and in the final moments of the play—after Kevin, Lena, Steve, Lindsey, Kathy, and Tom have all exited the house—Dan opens the trunk and reads Kenneth’s suicide note. As Dan reads, Kenneth can be seen descending the staircase in the year 1959. He sits by a window and begins to write his suicide note. When Bev enters and asks what he’s doing, he tells her he’s going to a job interview. She says, “I really believe things are about to change for the better.”