Caroline Robbins was born to a farming family in Middlesex, England. Her parents were strict Baptists, but she did not follow their faith, though she was proud of her nonconformist origins.
She attended Royal Holloway College for her bachelor's degree, and earned a PhD from London University in 1926 with a dissertation on Andrew Marvell. She then went to the USA and became a pioneering female British academic at American universities. She was a fellow at the University of Michigan, Ann Arbor, and an instructor at the college for women at Western Reserve University in Cleveland, Ohio, before becoming an instructor in British history at Bryn Mawr College, Pennsylvania, in 1929. She was a member of that department for 42 years, 12 of them as chairman. From 1960 until her retirement in 1971, she was Marjorie Walker Goodhart Professor. In 1932, she married (Stephen) Joseph Herben, a Bryn Mawr professor of English, but always used her maiden name. She was an influential teacher known for exacting standards. Her interest in early English republican thought led to her most significant work, The Eighteenth Century Commonwealthman (1959), a rich resource of previously neglected original materials. Cambridge University Press later commissioned her study, Two English Republican Tracts (1969). She received the Herbert Baxter Adams prize of the American Historical Association in 1960 and the American Historical Association award for scholarly distinction in 1989. She was elected a fellow of the Royal Historical Society and was commemorated in the annual Caroline Robbins lecture at the Institute of United States Studies at the University of London.