Sam Baldwin loses his wife, and moves to Seattle with his son Jonah in an attempt to start a new life. 18 months later, Sam is still grieving and Jonah is desperate for a new mother. Eventually, Jonah convinces Sam to pour his heart out live on the radio - he becomes an instant hit with thousands of female listeners and receives a deluge of letters of comfort. Listening in Baltimore, and inspired in equal parts by Sam's story and by classic Hollywood romance, is journalist Annie Reed. She writes to Sam and becomes convinced that they are destined to meet.
There are just two problems, though: Annie is engaged to someone else, and Sam doesn't know - yet - that they're made for each other.