Catharine Macaulay (née Sawbridge, later Graham; 23 March 1731 – 22 June 1791) was an English historian. She was the first Englishwoman to become a published historian and during her lifetime the world's only published female historian. Macaulay was the first English radical to visit America after independence, staying there from 15 July 1784 to 17 July 1785. Her visit included a visit to Mount Vernon where she met with George Washington. Macaulay's most prominent work was an eight-volume Whig history of England in which she argued that the people have the right to overthrow their monarch for their own natural rights.

Catharine Macaulay (née Sawbridge) was born in Olantigh, Wye, Kent. She was the daughter of John Sawbridge (1699–1762) and Elizabeth Wanley (died 1733) of Olantigh. Sawbridge was a landed proprietor from Wye, Kent, whose ancestors were Warwickshire yeomanry. Catherine's grandfather was a well-known and wealthy man who left her property, located at Olantigh in Kent. Her grandfather eventually ruined his reputation and lost much of what he had.

Macaulay was educated privately at home by a governess. This governess was not able to meet all of Macaulay's interests and curiosity and Macaulay read and developed her skills on her own.

In the first volume of her History of England, Macaulay claimed that from an early age she was a prolific reader, in particular of "those histories which exhibit liberty in its most exalted state in the annals of the Roman and Greek Republics… [from childhood] liberty became the object of a secondary worship".

However this account is at odds with what she told her friend Benjamin Rush, to whom she described herself as "a thoughtless girl till she was twenty, at which time she contracted a taste for books and knowledge by reading an odd volume of some history, which she picked up in a window of her father's house". She also told Caleb Fleming that she knew neither Latin nor Greek.

Little is known about her early life. In 1757, a Latin and Greek scholar, Elizabeth Carter, visited a function at Canterbury where she met Macaulay, then 26 years old. In a letter to a friend, Carter described Macaulay as a "very sensible and agreeable woman, and much more deeply learned than beseems a fine lady; but between the Spartan laws, the Roman politics, the philosophy of Epicurus, and the wit of St. Evremond, she seems to have formed a most extraordinary system".

On 20 June 1760 she married a Scottish physician, Dr. George Macaulay (1716–1766), and they lived at St James's Place, London. They remained married for six years until his death in 1766. They had one child together, Catharine Sophia. With Dr. Macaulay's encouragement, Macaulay began to write her history of England.^{[citation needed]} Her first volume was published in 1763. Nothing was published from 1768-1771. Macaulay moved to Bath in 1774. At age 47, she married her second husband, William Graham (then 21 years old), on 14 November 1778 The marriage caused some scandal but seemed to be a happy marriage despite outside opinions. Together they toured the United States and met with George Washington at Mount Vernon.

The second marriage coincided with the publication of the first volume of The History of England from the Revolution to the Present Time, in a Series of Letters to the Reverend Doctor Wilson (1778) in which she argued that the English Civil War had not gone far enough to eliminate the prerogatives of the crown. Her arguments against monarchy challenged moderate elements in the Whig party. Macaulay insisted that the civil war is a defense of the rights of the people against monarchs.