A charitable organization, or charity, is an organization whose primary objectives are philanthropy and social well-being (e.g. educational, religious or other activities serving the public interest or common good).

The legal definition of a charitable organization (and of charity) varies between countries and in some instances regions of the country. The regulation, the tax treatment, and the way in which charity law affects charitable organizations also vary. Charitable organizations may not use any of their funds to profit individual persons or entities. However, some charitable organizations have come under scrutiny for spending a disproportionate amount of their income to pay the salaries of their leadership.

Financial figures (e.g. tax refunds, revenue from fundraising, revenue from the sale of goods and services or revenue from investment, and funds held in reserve) are indicators to assess the financial sustainability of a charity, especially to charity evaluators. This information can impact on a charity's reputation with donors and societies, and thus the charity's financial gains.

Charitable organizations often depend partly on donations from businesses. Such donations to charitable organizations represent a major form of corporate philanthropy.

To meet the exempt organizational test requirements, a charity has to be exclusively organized and operated, and to receive and pass the exemption test, a charitable organization must follow the public interest and all exempt income should be for the public interest. For example, in many countries of the Commonwealth, charitable organizations must demonstrate that they provide a public benefit.

Until the mid-18th century, charity was mainly distributed through religious structures (such as the English Poor Relief Act 1601), almshouses, and bequests from the rich. Christianity, Judaism, and Islam incorporated significant charitable elements from their very beginnings, and dāna (alms-giving) has a long tradition in Hinduism, Jainism, Buddhism, and Sikhism. Charities provided education, health, housing, and even prisons. Almshouses were established throughout Europe in the Early Middle Ages to provide a place of residence for the poor, old, and distressed people; King Athelstan of England (reigned 924–939) founded the first recorded almshouse in York in the 10th century.

During the Enlightenment era, charitable and philanthropic activity among voluntary associations and affluent benefactors became a widespread cultural practice. Societies, gentlemen's clubs, and mutual associations began to flourish in England, with the upper classes increasingly adopting a philanthropic attitude toward the disadvantaged. In England, this new social activism led to the establishment of charitable organizations, which proliferated from the middle of the 18th century.

This emerging upper-class trend for benevolence resulted in the incorporation of the first charitable organizations. Appalled by the number of abandoned children living on the streets of London, Captain Thomas Coram set up the Foundling Hospital in 1741 to care for these unwanted orphans in Lamb's Conduit Fields, Bloomsbury. This institution, the world's first of its kind, served as the precedent for incorporated associational charities in general.