Sarah Trimmer (née Kirby; 6 January 1741 – 15 December 1810) was a writer and critic of 18th-century British children's literature, as well as an educational reformer. Her periodical, The Guardian of Education, helped to define the emerging genre by seriously reviewing children's literature for the first time; it also provided the first history of children's literature, establishing a canon of the early landmarks of the genre that scholars still use today. Trimmer's most popular children's book, Fabulous Histories, inspired numerous children's animal stories and remained in print for over a century.
Trimmer was also an active philanthropist. She founded several Sunday schools and charity schools in her parish. To further these educational projects, she wrote textbooks and manuals for women interested in starting their own schools. Trimmer's efforts inspired other women, such as Hannah More, to establish Sunday school programs and to write for children and the poor.
Trimmer's works are dedicated to maintaining many aspects of the social and political status quo. As a high church Anglican, she was intent on promoting the established Church of England and on teaching young children and the poor the doctrines of Christianity. Her writings outlined the benefits of social hierarchy, arguing that each class should remain in its God-given position. Yet, while supporting many of the traditional political and social ideologies of her time, Trimmer questioned others, such as those surrounding gender and the family.
Sarah Trimmer was born on 6 January 1741 in Ipswich, England to Joshua Kirby and Sarah (née Bell); her father was a noted artist and served as President of the Society of Artists of Great Britain. Trimmer had one younger brother, William; she was apparently the better writer, for she would sometimes compose his school essays for him. As a young girl, Trimmer attended Mrs. Justiner’s boarding school in Ipswich, an experience she always remembered fondly. In 1755, the family moved to London when her father, who had written several important works on perspective, became the tutor of perspective to the Prince of Wales. Because of her father's connections within the artistic community, Trimmer was able to meet the painters William Hogarth and Thomas Gainsborough as well as the by-then legendary writer and critic Samuel Johnson. She made a favourable impression on Johnson when she immediately produced her pocket copy of John Milton's Paradise Lost (1667) to help settle a dispute between her father and Johnson over a particular passage. Johnson, delighted that she admired Milton enough to carry his works with her at all times, "subsequently invited her to his house and presented her with a volume of his famous periodical The Rambler". In 1759, at the urging of his former pupil the Prince of Wales (soon to be George III), her father was made Clerk of the Works to the Royal Household at Kew Palace and the family moved to Kew. There she met James Trimmer, whom she married on 21 September 1762; after their marriage, the couple moved to Old Brentford.