Alice Sycamore and Tony Kirby come from two very different worlds. Alice's family is eccentric and carefree, living in a house brimming with peculiar but harmless activities. They believe in pursuing happiness rather than wealth. The head of the household, Grandpa Vanderhof, exemplifies this lifestyle, having left the corporate world years ago to focus on enjoying life. Meanwhile, Tony is the son of Anthony P. Kirby, a wealthy and ambitious banker intent on sealing a major deal that involves purchasing property around Alice's home. Despite their differing backgrounds, Alice and Tony fall in love and plan to get married.

Their engagement leads to a clash of worlds when the Kirbys have dinner at the Sycamore household, resulting in a whirlwind of misunderstandings and comic chaos. Tensions rise as the two families confront their contrasting values. While Alice wants to impress Tony's conservative parents, their quirky and unconventional behavior becomes an obstacle. The developing relationship faces further strain under the pressure from Anthony P. Kirby's business ambitions, which threaten to evict the Sycamores from their home. Confronted with these challenges, both families must reflect on what truly matters in life: material success or personal happiness.