Marchmont (Scottish Gaelic: Marc-Mhonadh) is a mainly residential area of Edinburgh, Scotland. It lies roughly one mile (1.5 kilometres) south of the Old Town, separated from it by The Meadows and Bruntsfield Links. To the west it is bounded by Bruntsfield; to the south-southwest by Greenhill and then Morningside; to the south-southeast by The Grange; and to the east by Sciennes.

The area is characterised by four- and five-storey tenements blocks built in the Scots Baronial style. Most of the area was developed in the 1870s and 1880s and there has been little change to its structure since then. Marchmont remains popular with older residents, young professionals and students. In 1987, it was designated as a conservation area, the boundaries of which were extended in 1996 to include the Meadows, Bruntsfield Links and immediately surrounding streets.

Marchmont was named after the 5th Earl of Marchmont, Hugh Hume Campbell, whose title in turn derives from the hill on which Roxburgh Castle was built. The name is Brittonic and probably means “the hill-pasture for horses”.

The area was developed as a planned middle-class suburb by Sir George Warrender (the son-in-law of Hugh Hume Campbell), who owned Bruntsfield House and the surrounding estate (which was also known as the Warrender Park) in the middle of the 19th century. This was at a time of rapid population growth in Edinburgh, stimulating a significant increase in the demand for housing. The original feuing plan laid out by architect David Bryce in 1869 called for mainly terraced villas, with a number of large, detached villas on Marchmont Road. However, this was superseded by a more comprehensive plan prepared by the firm of John Watherston & Sons. This proposed that all buildings were to be four- or five-storey tenements, some with commercial premises on the ground floor frontages.

Most of the buildings were completed in the 1870s and 1880s. The first tenements to go up were mostly in pink sandstone in the Scots Baronial style; these are by architects such as Edward Calvert. The later buildings, which were often in blonde sandstone and in a plainer, more uniform style, include works by Hippolyte Blanc, John Charles Hay and Thomas P. Marwick. Key buildings such as churches are mainly by the then city architect, Robert Morham.

Originally, the area was not allowed to have any premises selling alcohol, although that is no longer the case.

As was the usual practice at the time, the area's street names were derived from members of the developer's family or places associated with them. Sir George Warrender's wife, Helen, was the daughter of the 5th Earl of Marchmont, hence the name of the district. Thirlestane Street and Lauderdale Street were named in honour of Sir George's mother, who was the daughter of the Earl of Lauderdale and whose family seat was at Thirlestane Castle. Spottiswoode Street and Spottiswoode Road were named for John Spottiswoode, another Warrender relation, while Arden, as in Arden Street, was the family name of the Earl of Haddington, who married one of the Warrender daughters.

Due to its proximity to the city centre, the presence of local amenities, and generally being considered a pleasant area, Marchmont is considered a desirable location in which to live. This is reflected in its generally high property prices. It is popular with students, with both the University of Edinburgh and Edinburgh Napier University within easy walking distance, as well as with young professionals. This has resulted in a certain friction between permanent residents and temporary ones (many of whom are students), with the Marchmont Action Group Promoting Initiatives for the Environment (MAGPIE) unsuccessfully petitioning the Scottish Parliament in 2005 to impose quotas on shared accommodation by restricting the number of licences for Houses in Multiple Occupation (HMOs) granted for the area.