Ragged schools were charitable organisations dedicated to the free education of destitute children in 19th century Britain. The schools were developed in working-class districts and intended for society's most destitute youngsters who, it was argued, were often excluded from Sunday School education because of their unkempt appearance and often challenging behaviour. After a few of such schools were set up in the early 19th century by individual reformers, the London Ragged School Union was established in April 1844 to combine resources in the city, providing free education, food, clothing, lodging and other home missionary services for poor children. Although the Union did not extend beyond London, its publications and pamphlets helped spread ragged school ideals across the country before they were phased out by the final decades of the 19th century.

Working in the poorest districts, teachers (who were often local working people) initially utilised stables, lofts and railway arches for their classes. The majority were voluntary teachers, although a small number were employed. There was an emphasis on reading, writing, arithmetic and study of the Bible, and the curriculum expanded into industrial and commercial subjects in many schools. It is estimated that between 1844 and 1881 about 300,000 children went through just the ragged schools in London alone.

The Ragged School Museum in the East End of London, housed in buildings previously occupied by Dr. Thomas Barnardo, shows how a ragged school would have looked. It provides an idea of the working of a ragged school, although Thomas Barnardo's institution differed considerably in practice and philosophy from the schools accountable to the London Ragged School Union.