The orphan, who comes to be called Judy, does what she can to stand up for the younger children, frequently clashing with both Mrs. Lippett and the cold hearted trustees.

At one point she leads a rebellion against being served prunes with every meal and at another, steals a doll from a selfish rich girl to lend to a dying orphan.

Years later, wealthy Jervis Pendleton, a mysterious benefactor, pays to send Judy, now the oldest and most talented child in the orphanage, to college.

Judy proves popular with her wealthier and more "aristocratic" classmates, and writes a successful book to repay "Daddy-Long-Legs" the money he spent on her.

The plot uses a series of episodes, some separated by time gaps, many humorous, that often pose opposites, like rich and poor or male and female, to advance the story.