A foundling hospital was originally an institution for the reception of foundlings, i.e., children who had been abandoned or exposed, and left for the public to find and save. A foundling hospital was not necessarily a medical hospital, but more commonly a children's home, offering shelter and education to foundlings.

The antecedents of such institutions was the practice of the Catholic Church providing a system of relief, children being left (jactati) in marble shells at the church doors, and tended first by the matricularii or male nurses, and then by the nutricarii or foster parents. But it was in the 7th and 8th centuries that definite institutions for foundlings were established in such towns as Trèves, Milan and Montpellier.

Historically, care for foundlings tended to develop more slowly or with greater variation from country to country than, for example, care for orphans. The reason for this discrepancy was the perception that children abandoned by their parents carried with them a burden of immorality. Their parents tended to be unmarried and poor. Alleviating the burden of unwanted pregnancies was often seen as encouraging infidelity and prostitution. Thomas Malthus, for example, the noted English demographer and economist, made, in his The Principles of Population (vol. i. p. 434), a violent attack on foundling hospitals. He argued that they discouraged marriage and therefore population, and that even the best management would be unable to prevent a high mortality. He wrote: "An occasional child murder from false shame is saved at a very high price if it can be done only by the sacrifice of some of the best and most useful feelings of the human heart in a great part of the nation".