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.

Ernestine Moller Gilbreth Carey was an American writer.