Philanthropy is a form of altruism that consists of "private initiatives for the public good, focusing on quality of life". Philanthropy contrasts with business initiatives, which are private initiatives for private good, focusing on material gain; and with government endeavors that are public initiatives for public good, such as those that focus on the provision of public services. A person who practices philanthropy is a philanthropist.

The word philanthropy comes from Ancient Greek φιλανθρωπία (philanthrōpía) 'love of humanity', from philo- 'to love, be fond of' and anthrōpos 'humankind, mankind'. In the second century CE, Plutarch used the Greek concept of philanthrôpía to describe superior human beings.

During the Middle Ages, philanthrôpía was superseded in Europe by the Christian virtue of charity (Latin: caritas) in the sense of selfless love, valued for salvation and escape from purgatory. Thomas Aquinas held that "the habit of charity extends not only to the love of God, but also to the love of our neighbor".

Sir Francis Bacon considered philanthrôpía to be synonymous with "goodness", correlated with the Aristotelian conception of virtue as consciously instilled habits of good behaviour. Samuel Johnson simply defined philanthropy as "love of mankind; good nature". This definition still survives today and is often cited more gender-neutrally as the "love of humanity."^{[better source needed]}

In London, prior to the 18th century, parochial and civic charities were typically established by bequests and operated by local church parishes (such as St Dionis Backchurch) or guilds (such as the Carpenters' Company). During the 18th century, however, "a more activist and explicitly Protestant tradition of direct charitable engagement during life" took hold, exemplified by the creation of the Society for the Promotion of Christian Knowledge and Societies for the Reformation of Manners.

In 1739, Thomas Coram, appalled by the number of abandoned children living on the streets of London, received a royal charter to establish the Foundling Hospital to look after these unwanted orphans in Lamb's Conduit Fields, Bloomsbury. This was "the first children's charity in the country, and one that 'set the pattern for incorporated associational charities' in general." The hospital "marked the first great milestone in the creation of these new-style charities."

Jonas Hanway, another notable philanthropist of the era, established The Marine Society in 1756 as the first seafarer's charity, in a bid to aid the recruitment of men to the navy. By 1763, the society had recruited over 10,000 men and it was incorporated in 1772. Hanway was also instrumental in establishing the Magdalen Hospital to rehabilitate prostitutes. These organizations were funded by subscriptions and run as voluntary associations. They raised public awareness of their activities through the emerging popular press and were generally held in high social regard—some charities received state recognition in the form of the Royal Charter.

Philanthropists, such as anti-slavery campaigner William Wilberforce, began to adopt active campaigning roles, where they would champion a cause and lobby the government for legislative change. This included organized campaigns against the ill-treatment of animals and children and the campaign that succeeded in ending the slave trade throughout the Empire starting in 1807. Although there were no slaves allowed in Britain itself, many rich men owned sugar plantations in the West Indies, and resisted the movement to buy them out until it finally succeeded in 1833.