Cheaper by the Dozen is a semi-autobiographical novel written by Frank Bunker Gilbreth Jr. and Ernestine Gilbreth Carey, published in 1948. The novel recounts the authors' childhood lives growing up in a household of 12 children. The bestselling book was later adapted into a feature film by Twentieth Century Fox in 1950 and followed up by the sequel, Belles on Their Toes (1950), which was adapted as a 1952 film.

Frank Bunker Gilbreth Jr. was an American journalist and author. He co-authored, with his sister Ernestine, the autobiographical bestsellers Cheaper by the Dozen and Belles on Their Toes. Under his own name, he wrote multiple additional books, such as Time Out for Happiness and Ancestors of the Dozen, and a long-running newspaper column.