The ONE Thing: The Surprisingly Simple Truth About Extraordinary Results by Gary Keller and Jay Papasan is a productivity and focus book that argues extraordinary results come from narrowing attention to the single most important task at any given time.

The book introduces the idea of “the ONE thing,” the highest-leverage action that makes everything else easier or unnecessary. It challenges multitasking and scattered effort, showing how success is built through prioritization, habit formation, and disciplined focus over time. Through examples from business, real estate, and personal development, the authors explain how clarity drives performance and how asking the right focusing question—what is the ONE thing I can do such that by doing it everything else becomes easier or unnecessary—can reshape decision-making and outcomes across work and life.