The film follows Cary Scott (Jane Wyman), a wealthy, middle-aged widow living in a pristine New England town. She falls in love with Ron Kirby (Rock Hudson), a younger, working-class gardener and arborist. Despite their genuine connection, Cary’s adult children and her social circle disapprove of the relationship, viewing Ron as socially inferior. Under pressure, Cary breaks off the engagement. She eventually realizes her mistake but suffers a near-fatal accident. Ron rescues her, and the film ends with them tentatively reconciled, though the future remains uncertain.

The title All That Heaven Allows is ironic. The "heaven" on offer is not the pearly gates of theology, but the earthly paradise of romantic fulfillment and authentic existence. What does society allow? Very little. It allows luxury but not passion. It allows propriety but not truth. It allows a television set, but not a lover who sees your soul.