The Clapham Sect or Clapham Saints were a group of Christian influential like-minded Church of England social reformers based in Clapham, London at the beginning of the 19th century (active c. 1790–1830). They are described by the historian Stephen Tomkins as "a network of friends and families in England, with William Wilberforce as its centre of gravity, who were powerfully bound together by their shared moral and spiritual values, by their religious mission and social activism, by their love for each other, and by marriage".
Campaigns and successes 
Its members were chiefly prominent and wealthy evangelical Anglicans who shared common political views concerning the liberation of slaves, the abolition of the slave trade and the reform of the penal system.
The group's name originates from Clapham Common, an area south-west of London then surrounded by fashionable villas. Here both Wilberforce and Thornton, the sect's two most influential leaders, resided and many of the group's meetings were held in their houses. They were supported by Beilby Porteus, Bishop of London, who sympathised with many of their aims. The phrase 'Clapham Sect' was a later invention by James Stephen in an article of 1844 which celebrated and romanticized the work of these reformers. In their own time the group used no particular name, but they were lampooned by outsiders as "the saints".
The group published a journal, the Christian Observer, edited by Zachary Macaulay and were also credited with the foundation of several missionary and tract societies, including the British and Foreign Bible Society and the Church Missionary Society.
They founded Freetown in Sierra Leone, the first major British colony in Africa, whose purpose in Thomas Clarkson's words was "the abolition of the slave trade, the civilisation of Africa, and the introduction of the gospel there".
After many decades of work both in British society and in Parliament, the group saw their efforts rewarded with the final passage of the Slave Trade Act in 1807, banning the trade throughout the British Empire and, after many further years of campaigning, the total emancipation of British slaves with the passing of the Slavery Abolition Act in 1833. They also campaigned vigorously for Britain to use its influence to eradicate slavery throughout the world.
Other societies that they founded or were involved with included the Anti-Slavery Society, the Abolition Society, the Proclamation Society, the Sunday School Society, the Bettering Society, and the Small Debt Society.
The Clapham sect have been credited with playing a significant part in the development of Victorian morality, through their writings, their societies, their influence in Parliament, and their example in philanthropy and moral campaigns, especially against slavery. In the words of Tomkins, "The ethos of Clapham became the spirit of the age".
Members of the Clapham Sect included:
- Thomas Fowell Buxton (1786–1845), MP and brewer
- William Dealtry (1775–1847), Rector of Clapham, mathematician
- Edward James Eliot (1758–97), parliamentarian
- Thomas Gisbourne (1758–1846), clergyman and author
- Charles Grant (1746–1823), administrator, chairman of the directors of the British East India Company, father of the first Lord Glenelg
- Katherine Hankey (1834–1911), evangelist
- Zachary Macaulay (1768–1838), estate manager, colonial governor, father of Thomas Babington Macaulay
- Hannah More (1745–1835), writer and philanthropist
- Granville Sharp (1735–1813), scholar and administrator
- Charles Simeon (1759–1836), Anglican minister, promoter of missions
- James Stephen (1758–1832), Master of Chancery, great-grandfather of Virginia Woolf.
- Lord Teignmouth (1751–1834), Governor-General of India
- Henry Thornton (1760–1815), economist, banker, philanthropist, MP for Southwark, great-grandfather of writer E.M. Forster
- Henry Venn (1725–97), founder of the group, father of John Venn and great-grandfather of John Venn (originator of the Venn diagram)
- John Venn (1759–1813), Rector of Holy Trinity Church, Clapham
- William Wilberforce (1759–1833), MP successively for Kingston upon Hull, Yorkshire and Bramber, leading abolitionist
- Tomkins, Stephen The Clapham Sect: How Wilberforce’s circle changed Britain (Oxford: Lion, 2010), p1
- Tomkins, The Clapham Sect, 11
- Tomkins The Clapham Sect, p248