High in the Swiss Alps, Heidi, a five-year-old orphan, comes to live with her grandfather. His neighbors say he is a fierce old hermit, of whom they are all afraid. Heidi, however, proves to be a remarkable, unaffected child, who quickly charms her grandfather. In fact, for Heidi, nothing could be better than living with him. She enjoys a genuine enthusiasm for life: for the goats, which she helps Peter to tend; for the spring flowers on the Alm; for the thick slices of bread and cheese that her grandfather prepares for her; and for the simple hay bed that she occupies in the loft of his hut.

However, her Aunt Dete doesn't understand, and it is a sad day when she takes Heidi to live in a strange city with a strange family who want a companion for their young invalid daughter named Klara. Heidi does her best to be a friend to Klara, but her longing for home becomes too much to bear.