Downe, formerly Down (/daʊn/), is a village in Greater London, England, located within the London Borough of Bromley, which formed part of Kent until 1965, and is beyond London's contiguous urban area. Downe is 3.4 miles (5.5 km) south west of Orpington and 14.2 miles (22.9 km) south east of Charing Cross. Downe lies on a low ridge (an outlier of the North Downs), and much of the centre of the village is unchanged; the former village school now acts as the village hall. The word Downe originates from the Anglo Saxon word dūn, latterly down, hence the South and North Downs. In April 1965, much of Orpington Urban District, including Downe, was transferred from the historic county of Kent and placed within the newly created London Borough of Bromley.

Lord Simon de Manning, a former Lord of the Manor of nearby Kevington, then in Kent, and holder of the land which now includes Downe, was a grandson of Rudolph de Manning, Count Palatine, who married Elgida, aunt of King Harold I, of England; he was the royal Standard Bearer to King Richard the Lionheart, who carried the Royal Standard to Jerusalem in 1190, during the First Crusade. In England, the forms Earl Palatine and Palatine Earldom are preferred.

As well as Downe, Kevington Manor then included the areas which later became Berry's Green, Luxted, Single Street, Westerham Hill, and Leaves Green. These (excluding Kevington), together formed the Darwin (ward), Greater London's largest electoral ward), as it was first constituted in 1965. The current elected political party's website (2022), states that the ward includes Cudham, Leaves Green, Leavesden Estate, Westerham Hill, Beechwood, Berry's Green, and Pratts Bottom.

The name of the village seems to have been spelled in a variety of ways over time. In the postal directories of the mid-19th century it is named as Down. In 1869, Charles Darwin wrote to a correspondent that the Post Office had changed the head Post Town to Beckenham rather than Bromley. In it he also mentions refusal to change the name of his house (see below), implying that the change from Down to Downe occurred at the same time.

It has been said that the village name change was a result of post being misdirected to Co. Down in Ireland, but there is no evidence for this. It is equally possible that it was simply a case of the Post Office standardising what had previously been variable spelling. In any event, by 1882 Kelly's Directory was using Downe.

Charles Darwin lived in Down House for 40 years, from 1842 until he died there in 1882. He became a close friend of Sir John Lubbock, 3rd Baronet, who lived nearby at the Lubbock's High Elms estate on the other side of the village. A favourite place of Darwin's was Downe Bank, now a nature reserve and Site of Special Scientific Interest, and several members of his family are buried in the graveyard of St Mary's Church.

Down House and the surrounding area has been nominated by the Department of Culture, Media and Sport to become a World Heritage Site. However, this decision has been deferred.

Since 2019, the local Member of Parliament has been Gareth Bacon of the Conservative Party. In the 2017 General Election, with a majority of 19,453 votes (38.5%), Orpington was the safest Conservative Parliamentary seat in London.

One councillor is elected every four years to Bromley London Borough Council. To date, the Darwin ward has only been represented by representatives from the Conservative Party. It is the largest Greater London ward, and includes Berry's Green, Single Street, Luxted, Leaves Green, Westerham Hill, and Cudham.

Darwin ward 2018

Party		Candidate	Votes	%	±%
	Conservative	Richard Scoates	1,201	72.8
	Labour	Frank Evans	185	11.2
	Liberal Democrats	Millicent Scott Brooks	133	8.1
	Green	Jan Wilson	130	7.9
Turnout			1,649	40.0
	Conservative hold		Swing

Darwin ward 2014 (1)

Party		Candidate	Votes	%	±%
	Conservative	Richard Scoates	987	51.2
	UKIP	Eric Hayward	681	35.3
	Labour	John Evans	105	5.4
	Green	Eileen Galloway	89	4.6
	Liberal Democrats	William Ritchie	45	2.3
Majority			306
Turnout			1,927
	Conservative hold		Swing

Downe is the location of Buckston Browne Farm, built in 1931 as a surgical research centre by the Royal College of Surgeons (RCS). In the 1980s, the farm caused controversy because of its use of vivisection techniques, and in August 1984 it was raided by anti-vivisection activists.

The farm has now been made into four houses.

There are two scout campsites in the Downe area:

• The Downe Scout Activity Centre consisting of 86 acres (350,000 m) of woodland and open fields is just outside the village.
• The Greenwich (one of the Districts of the Greater London South Scout county) District campsite is also nearby.

The closest National Rail stations to Downe are at Orpington and Hayes, located 4.5 and 4.7 miles away respectively.

The village is served by London Buses routes 146 and R8 which provide connections to Bromley, Orpington and Biggin Hill.

• Bill Hunter Christie (1922–97), lobbyist for the Falkland Islanders
• Charles Darwin (1809–82), biologist, naturalist and geologist
• Horace Darwin (1851–1928), civil engineer and Fellow of Trinity College, Cambridge
• Nigel Farage (born 1964), former leader of UKIP and Member of European Parliament for South East England.
• Charles Hayes (1678–1760), mathematician and chronologist
• John Lubbock (1803–65), banker, barrister, mathematician and astronomer
• John Lubbock (1834–1913), banker, biologist, archaeologist and Liberal politician
• Mark Lubbock (1898–1986), conductor and composer of operetta and light music
• Herbert Newton Casson (1869–1951), journalist and author, founder of Efficiency magazine
• Olive Willis (1877–1964), founder of Downe House School

• Cudham
• Berry's Green
• Luxted
• Single Street
• Farnborough
• Keston
• Orpington

• Audio tour of Downe and Down House
• Downe Bank Nature Reserve
• Darwin at Downe - World Heritage Site nomination
• Homepage of Stage Door Theatre Group, Downe