Nelson was born in Chicago, Illinois to Viola, a dancer, and Richard Finis Nelson, an accounting-systems analyst and some times sales representative. During Nelson's childhood, the family moved frequently to accommodate his father's work, but they settled for long stretches in Gary, Indiana, the outskirts of Philadelphia, and finally in a suburb of Detroit. Nelson's earliest theatrical influences were in musical theatre, and he estimates that he saw more than twenty-five musicals before ever seeing his first straight play.
He graduated from Hamilton College in 1972, and received an honorary Doctor of Literature degree from Hamilton College in 2004.
He married Cynthia Blair Bacon on May 21, 1972; they have two children, Zoe (b. 1983) and Jocelyn (b. 1988).
He has worked with the Royal Shakespeare Company, and had ten plays produced there. Those plays include: Principia Scriptoriae (1986), Some Americans Abroad (1989), Two Shakespearean Actors (1990),Columbus and the Discovery of Japan (1992), Misha's Party (1993),New England (1994),The General From America (1996) and Goodnight Children Everywhere (1997).
In November 2006, Frank's Home, about two days in the life of Frank Lloyd Wright, premiered in Chicago, Nelson's home town, at the Goodman Theatre (in association with Playwrights Horizons). In an interview in The Brooklyn Rail at the time of its New York debut, Nelson offers advice to young writers: "My advice is always to write, to write what really matters. I ask my students two questions: Why did you write it? And should I watch it? People ask about structure, form, character development, and I’m not even sure what all of that means. Try not to second guess yourself. Form will come if you focus on what you want to say with truth and honesty. Structure is the hand that holds up what you want to say." From 2005 to 2008, Nelson was the chair of the playwriting department at the Yale School of Drama.
The Apple Family plays
From 2010 to 2013, Nelson wrote and directed four plays centered around the Apple Family, a fictional household set in Rhinebeck, New York with each play focused on either an election or a significant historical anniversary. The main characters are three adult sisters, Barbara, Marian and Jane – called a "Chekhovian family pod" by the Variety reviewer.
The first play in the series, That Hopey Changey Thing, focused on the 2010 midterm elections and opened on election night, November 2, 2010. The second play, Sweet and Sad (2011), depicts the family on the tenth anniversary of the September 11 attacks. The third play, Sorry, opened on November 6, 2012, and takes place during the 2012 presidential election. The final play, Regular Singing (2013), is set on the 50th anniversary of the JFK assassination. Each play debuted off-Broadway at The Public Theater, featuring essentially the same cast members in each subsequent production. With the opening of Regular Singing in 2013, the Public Theater presented the entire series in repertory.
The cast of That Hopey Changey Thing, Sweet and Sad, and Sorry featured Jon DeVries as Benjamin Apple, Maryann Plunkett as Barbara Apple, Jay O. Sanders as Richard Apple, Shuler Hensley as Tim Andrews, Laila Robins as Marian Apple Platt and J. Smith-Cameron as Jane Apple Halls. The cast of Regular Singing included the first three casts with the exceptions of Steven Kunken as Tim Andrews and Sally Murphy as Jane Apple Halls.
On April 29, 2020, the Public live-streamed a new Apple Family play, What Do We Need to Talk About?. Again directed by Nelson, it reunited the cast from Regular Singing. The characters, now seven years older, meet by video during the COVID-19 pandemic.
Nelson has written a new trilogy, titled The Gabriels: Election Year in the Life of One Family, focusing on the Gabriel family during the 2016 presidential election year. The same cast appears in all three plays: Meg Gibson (Karin Gabriel), Lynn Hawley (Hannah Gabriel), Roberta Maxwell (Patricia Gabriel), Maryann Plunkett (Mary Gabriel), Jay O. Sanders (George Gabriel), and Amy Warren (Joyce Gabriel). The first play, Hungry, opened off-Broadway at the Public Theatre on February 27, 2016 (previews), and officially on March 4, directed by Nelson. The next play in the trilogy, What Did You Expect?, opened on September 10, 2016, in previews, officially on September 16 and closed on October 9. The final play, Women of a Certain Age, opened on election night, November 8, 2016. and ran to December 4. The three plays ran in repertory December 10 to 18.
Hungry is set in Dutchess County, New York. The family of the recently deceased Thomas Gabriel are in the kitchen to prepare dinner. The group includes Thomas's widow, Mary; his sister, Joyce; his brother George and his wife Hannah; his elderly mother Patricia; and his first wife Karin. For dinner, the group peels apples for apple crisp and makes ratatouille and pasta. Referring to the political campaign, one character says: "God, it's going to be a long eight months."What Did You Expect?, also set in Rhinebeck, takes place six months after Hungry. Patricia has taken a roommate at her retirement community, and her debts are the focus of the play. The family prepares for a picnic as they deal with their "fears of the post-recession world." In Women of a Certain Age, set between 5 pm and 7 pm on election night, the Gabriels have gathered for dinner. George has picked up their son from college to vote and has driven him back. Joyce is at home and Patricia has also joined the group. The play ends without revealing the winner of the election.Ben Brantley wrote: "Far more than in any of his other plays, Mr. Nelson comes close here to capturing the elusive, expansive comic sadness we associate with his beloved Chekhov. That Chekhovian sense of time fading even as we inhabit it thrums through both the talk and the silences."
The Gabriels played an engagement at the Kennedy Center (Washington, DC) in January 2017 and then played at The Perth International Arts Festival (Australia) on February 11–18, and the Hong Kong Arts Festival on February 22–26. The original cast performed.
In 2019 Nelson added to the Rhinebeck Panorama with The Michaels, which ran at the Public October 19 – December 1, 2019. As with the Apple and Gabriel family plays it takes place around a meal, this time in the kitchen of Rose Michael, a celebrated choreographer.
Nelson directed a cast made up of Charlotte Bydwell as Lucy Michael, Haviland Morris as Irenie Walker, Maryann Plunkett as Kate Harris, Matilda Sakamoto as May Smith, Jay O. Sanders as David Michael, Brenda Wehle as Rose Michael, and Rita Wolf as Sally Michael.