Caroline Fox (24 May 1819 – 12 January 1871) was a Cornish diarist. She was the daughter of Robert Were Fox FRS of the influential Fox family of Falmouth and his wife, Maria Barclay. She was the younger sister of both Barclay Fox, also a diarist, and Anna Maria Fox.
Caroline was well known as the author of a diary, recording memories of many distinguished people, such as John Stuart Mill, John Sterling and Thomas Carlyle. Selections from her diary and correspondence (1835–1871) were published under the title of Memories of Old Friends: Caroline Fox of Penjerrick, Cornwall (edited by H. N. Pym, 1881; 2nd edition, 1882). A selection from the Victorian edition was published in 1972.
She died on 12 January 1871 and was buried in the Quaker Burial Ground at Budock.