Elizabeth Montagu (née Robinson; 2 October 1718 – 25 August 1800) was a British social reformer, patron of the arts, salonnière, literary critic and writer, who helped to organize and lead the Blue Stockings Society. Her parents were both from wealthy families with strong ties to the British peerage and learned life. She was sister to Sarah Scott, author of A Description of Millenium [sic] Hall and the Country Adjacent. She married Edward Montagu, a man with extensive landholdings, to become one of the richer women of her era. She devoted this fortune to fostering English and Scottish literature and to the relief of the poor.

She was born in Yorkshire to Matthew Robinson (1694–1778) of West Layton and Edgeley in Yorkshire, and Elizabeth daughter of Robert Drake of Cambridge, by his wife Sarah Morris, daughter of Thomas Morris of Mount Morris, Monks Horton. Elizabeth was the eldest of their three daughters. Conyers Middleton, the prominent Cambridge don, was the second husband of her Drake grandmother Sarah Morris. Between 1720 and 1736 the family owned part of what is now a National Trust property: Treasurer's House, in York. Elizabeth and her sister Sarah, the future novelist Sarah Scott, spent time as children on extended stays with Dr Middleton, as both parents were somewhat aloof. The two girls learned Latin, French, and Italian and studied literature. As a child, Elizabeth and Sarah, in particular, were very close, but grew apart after Sarah became sick with smallpox.

While young, Elizabeth became a friend of Lady Margaret Harley, later the Duchess of Portland, the only surviving child of Edward Harley, 2nd Earl of Oxford and Earl Mortimer. Lady Margaret and Elizabeth corresponded weekly when apart and were inseparable when together. She spent time with Lady Margaret in London and met many of the celebrated figures of the 1730s, including the poet Edward Young and the religious thinker Gilbert West. In Lady Margaret's household, men and women spoke as equals and engaged in witty, learned banter. Mrs Montagu later used this model of intellectual discourse in her salons. Visits to Lady Margaret became more important to Elizabeth when her mother inherited a country seat in Kent and made that her home, with her daughters.

In 1738, Montagu wrote to Harley explaining that she had no desire for men or marriage. She saw marriage as a rational and expedient convention and did not suppose it possible to love a man. In 1742 she married Edward Montagu, grandson of the Edward Montagu, 1st Earl of Sandwich, who owned numerous coal mines and had several rents and estates in Northumberland. She was 24 and he was 50 years old. The marriage was advantageous, but apparently not very passionate. All the same, she bore a son, John, the next year, and she loved her child immensely. When the child died unexpectedly in 1744, she was devastated. She and Edward remained friendly throughout their remaining time together, but there were no more children or pregnancies. Prior to the loss of her son, she had not been very religious, but his death brought her to take religion increasingly seriously. Meanwhile, her sister, Sarah Scott, was also growing increasingly devout.

Elizabeth was accompanied most of the time by a lady's companion, in a role derived from that of a royal lady in waiting. A companion would be expected to carry things and aid Elizabeth on her daily round. Barbara Schnorrenberg suggests that Sarah Scott took this function and adds that there is good reason to suggest that Scott married poorly to escape it (Schnorrenberg 723). After Elizabeth's mother died, her father moved to London with his housekeeper or possibly mistress, giving no money at all to his children. When Sarah was removed from her bad marriage, Elizabeth's father (whose ward she was) not only gave her no financial help, but forbade either Elizabeth or Matthew, her brother, from relieving her distress.

Beginning in 1750, she and Edward established a routine, where they would winter in London in Mayfair and then in the spring go to Sandleford in Berkshire, which had been his since 1730. He would then go on to Northumberland and Yorkshire to manage his holdings, while she would occasionally accompany him to the family manor house at East Denton Hall, a mansion dating from 1622 on the West Road in Newcastle upon Tyne.

She was a shrewd businesswoman, despite affecting to patronise Northumbrian society for its practical conversation. Though acting as Lady Bountiful to miners and their families, she was pleased at how cheap this could be. She was also glad to note that "our pitmen are afraid of being turned off and that fear keeps an order and regularity amongst them that is very uncommon." Elizabeth enjoyed hearing the miners singing in the pit, but found, alas, that their dialect (Geordie) was "dreadful to the auditors' nerves." Horace Walpole wrote to George Montagu in 1768: "Our best sun is Newcastle coal."

In London during the 1750s, Elizabeth began to be a celebrated hostess. She organized literary breakfasts with Gilbert West, George Lyttelton and others. By 1760, these had turned into populous evening entertainments. Card playing and strong drink were forbidden from these convocations, which came to be now known as Blue Stocking events.