Chance, a simple-minded gardener, has spent his entire life confined to the townhouse of a wealthy employer, tending the garden and receiving all his information from television. When his benefactor dies, Chance is forced to leave the only home he has ever known. Naively wandering the streets of Washington D.C., he has a minor accident with the limousine of Eve Rand, the wife of a powerful and influential businessman, Ben Rand. Mistaking him for an educated man of means due to his appearance and impeccable manners, she takes him to their estate to recover.

Upon meeting Ben, Chance's simplistic gardening talk and demeanor are misunderstood as profound metaphors and wisdom. As Chance encounters various influential figures, his words are further interpreted as deep insights into economics and politics. This misunderstanding propels him to considerable fame and influence, with important political advisors and even the President seeking his counsel. His rise through Washington's elite circles continues under the guise of profound simplicity, affecting those around him in unexpected ways.