Alvin Straight, a stoic and elderly man living in rural Iowa, learns that his estranged brother, Lyle, has suffered a stroke. Despite having numerous health issues himself and lacking a driver’s license, Alvin feels compelled to reconcile with Lyle while there’s still time. With unwavering determination, he opts to make the journey on his terms—traveling 240 miles on a modest lawnmower. This unusual decision astonishes his daughter, Rose, who supports his resolve despite its impracticality. Alvin’s journey begins with small challenges, from mechanical trouble with his lawnmower to understated interactions with kind strangers who are curious about his mission.

As Alvin makes slow but steady progress, the people he encounters along the way reveal their own stories and struggles. Alvin's advice and gentle wisdom leave a positive impact on those he meets, highlighting the simplicity and strength of human connection. Through honest conversations, shared meals, and moments of silence under the expansive Midwestern sky, Alvin reflects on his past decisions, the passage of time, and familial bonds. The humble lawnmower becomes a symbol of his perseverance, as well as his way of confronting unfinished business. Each mile traveled brings Alvin closer not only physically to his brother but emotionally as well, setting the stage for a personal revelation as he approaches the conclusion of his meaningful journey.