Margaret McMillan (20 July 1860 – 27 March 1931) was a Christian Socialist (Simkin 1997) and member of the Fabian Society. Working in deprived districts, notably Bradford and Deptford, she agitated for reforms to improve the health of young children, wrote several books on nursery education and pioneered a play-centred approach that has only latterly found wide acceptance.
Margaret McMillan, was born to James and Jean McMillan in Westchester County, New York, on 20 July 1860. Her parents, were from Inverness but had emigrated to the United States in 1840. When she was four, an epidemic of Scarlet fever killed her father and sister and left Margaret deaf (she recovered her hearing at the age of fourteen). Thereupon Mrs. McMillan returned to Scotland with her daughters Margaret and Rachel McMillan, where both attended the Inverness High School. Jean McMillan died in 1877. Margret went on to study Psychology and Physiology, followed by Languages and Music in Germany. .
In 1887 Rachel was introduced to Christian socialism and read articles by William Morris and William Thomas Stead and after July 1888 joined her sister in London. Here she converted Margaret to socialism and they together attended political meetings, where they met William Morris, H. M. Hyndman, Peter Kropotkin, William Stead and Ben Tillett. In 1889, Rachel and Margaret helped the workers during the London Dock Strike. In 1892 they moved to Bradford. There they joined the Fabian Society, the Labour Church, the Social Democratic Federation and the Independent Labour Party (ILP).