Lights come up on an almost bare stage, where we see Grandpa Hoover, late sixties and a little worse for the wear, snorting something off of a dining room table. Opposite Grandpa is Frank, a man in a wheelchair with bandages on his wrist from a recent suicide attempt (“Prologue”).

The rest of the Hoover family enters, including Sheryl Hoover, the matriarch of the family and Frank’s older sister. Sheryl’s husband, Richard, a self-help entrepreneur and Grandpa’s son, and their two children – teenaged Dwayne, who recently took a vow of silence, and ten-year-old Olive, an aspiring beauty pageant queen (“The Way of the World”).

Assembling in the dining room for a KFC dinner, Frank questions Dwayne’s motives for taking a vow of silence for the last 85 days – refusing to speak until he attends the Air Force Academy and becomes a test pilot. Richard, Olive and Grandpa arrive after practicing some new moves for future pageants, high off of the rush of a recent runner-up placement. The dinner is interrupted by a message that's been left on the machine from Uncle Jeff, who informs the family that the winner of the recent pageant that Olive was in had to forfeit her crown, making Olive the winner. Olive is thrilled with this news and immediately begins to pack. The rest of the family figures out logistics: Richard has to forgo staying home in case a book agent contacts him in order to drive the stick shift Volkswagen Van, Grandpa must go as Olive’s coach, Frank must go because his doctor’s told Sheryl not to leave him alone and Dwayne must go because he is too young for a weekend alone.  They share the news with Olive that the whole family will be chaperoning to the pageant (“For the First Time in My Life”).

The whole family has loaded into the bus on their way to California. During the long car ride, we learn that Frank’s attempt at suicide was triggered by the loss of his first love, a graduate student of his named Joshua Rose. Another Proust scholar named Dr. Lawrence Sugarman wooed Joshua.

Hours pass. Grandpa is now seated with Dwayne and offers him some unsolicited advice (“The Happiest Guy in the Van”). Suddenly there is a loud pop as smoke begins to fill the van. The clutch cable has broken without a mechanic nearby and the whole family must push the van to get it moving and back on the road (“Pushing the Bus”).

Continuing towards California, Sheryl and Richard reminisce about all of the years with the Volkswagen Van. Sheryl and Richard flashback 17 years to their college days and are alone in the back of the van. Sheryl tells Richard that her period is late and they may be pregnant. They discuss what’s to come and weigh their options (“Always Make Me Proud”).

Back in present time, the family is stretching their legs, and Olive asks for ice cream. Richard tells her that eating too much ice cream can cause her to get a belly. He goes off, and Olive escapes to her imagination (“Poor Olive”). She opts for a Coke Zero instead and practices her routine.

Frank has an unexpected encounter in the bathroom with his former lover, Joshua Rose, who happens to be in Sedona for a conference with Dr. Larry Sugarman. Frank gives them both a piece of his mind (“How Have I Been?”).

A frustrated Frank rejoins the family, and all listen to Richard on the payphone with Stan, a prospective publisher for Richard’s book... the news is not good. In frustration, they begin pushing the bus to get it moving, realizing after acceleration that they have left Olive behind. Richard makes a quick U-turn to pick her up and then drives in silence. Grandpa breaks the silence by trying to console Richard. They reach their motel in California.

The family retires to their various rooms in the hotel. Frank and Dwayne share a room, Olive and Grandpa in another and Sheryl and Richard in the last (“Motel Sequence – Part 1”). Grandpa reassures Olive that she is “The Most Beautiful Girl in the World.” Sheryl and Richard argue (“Something Better Better Happen”) until Olive, who reveals that she thinks Grandpa is sick, interrupts them.

In a hospital waiting room, the family is told that Grandpa has died. Instead of waiting and handling the death of Grandpa, the family stages a coup to escape with Grandpa and not miss the Little Miss Sunshine pageant (“Nothing Gets in the Way”). After a successful escape, the family is back on the road (“Something Better – Reprise”).

To pass the time in the van, Olive and Dwayne take eye tests from the hospital. It is discovered during another test that Dwayne is colorblind, rendering him inapplicable for flight school. Dwayne breaks his vow of silence and vents his many frustrations (“Dwayne”).

The family finally arrives at the pageant a few minutes late and, after some negotiating, get Olive registered. Richard begins to go through his father’s belongings (“What You Left Behind”).

The pageant begins with hosts, Buddy and Miss California (“LMS Pageant Theme”). Richard panics at the thought of Olive failing and runs off to stop her from performing. Sheryl stops Richard from projecting his fear of failure onto Olive (“The Way of the World”). They wish Olive luck one last time, and she goes on (“Shake Your Badonkadonk”). Buddy tries to stop the performance, but the whole family joins Olive onstage to encourage her, instead.

In the parking lot after the pageant, we learn that Olive came in last. The family breaks into arguments but decide to enjoy the rest of the weekend and deal with their issues when they get home (“Finale”).