Catherine Littlefield was born on February 17, 1755, on Block Island off the coast of Rhode Island. Her father, John Littlefield, served in the Rhode Island legislature, and her mother, Phebe Ray, was a descendant of the earliest settlers of Block Island. Her mother died when Catharine was ten years old, and she was sent to live with her aunt and uncle, Catharine Ray Greene and William Greene – the future governor of the state – in East Greenwich, Rhode Island.

Her aunt, an attractive energetic woman who was known as a charming hostess, took over the role of Catherine’s mother, and supervised her education as a young woman of the upper classes. Present during her aunt’s many social gatherings, Catherine caught the interest of several of their bachelor acquaintances when she came of age. A notable visitor was Benjamin Franklin, who had been a close friend of Aunt Catharine.