The Adam style (also called Adamesque or the Style of the Brothers Adam) is an 18th-century neoclassical style of interior design and architecture, as practised by Scottish architect William Adam and his sons, of whom Robert (1728–1792) and James (1732–1794) were the most widely known.

The Adam brothers advocated an integrated style for architecture and interiors, with walls, ceilings, fireplaces, furniture, fixtures, fittings and carpets all being designed by the Adams as a single uniform scheme. Their style is commonly known under the mistaken plural "Adams style".

The Adam style found its niche from the late 1760s in upper-class and middle-class residences in 18th-century England, Scotland, Russia (where it was introduced by Scottish architect Charles Cameron), and post-Revolutionary War United States (where it became known as Federal style and took on a variation of its own). The style was superseded from around 1795 onwards by the Regency style and the French Empire style.

During the 18th century there was much work for eager architects and designers, as Britain experienced a boom in the building of new houses, theatres, shops, offices and factories, with towns growing rapidly due to the onset of the Industrial Revolution. The emphasis was on modernisation, with regulations being introduced to clean up the nation's streets, promoting the re-paving of roads and pavements, improving drainage and street lighting, and better fireproofing of buildings with the widespread use of brick and stone. Speculative building was rife, with some developers focussing on high speed and low cost. Sometimes, newly built houses collapsed due to poor workmanship; whilst others continually shifted on their foundations, giving rise to the phrase "things that go bump in the night", as mysterious crashes, creaks and thuds were heard by their inhabitants late at night. London experienced major expansion, with the newly built West End, which included the elegant squares of Mayfair; areas of the East End of London were also developed, such as the new terraces in Spitalfields. The cities of Edinburgh, Bristol and Dublin were all expanded and modernised. Birmingham was described in 1791 as being the "first manufacturing town in the world". Manchester and Liverpool each saw their population triple between 1760 and 1800. New towns, like Bath, were constructed around natural spas. Old medieval cities and market towns, such as York and Chichester, had their buildings re-fronted with brick or stucco, plus new sash windows, to give the impression of modernity, despite the underlying structures remaining medieval.

The Neoclassical style was all the vogue throughout the 18th century, and many style guides were published to advise builders how their finished properties should look. Influential guides included Stephen Riou's The Grecian Orders (1768), and Batty Langley's A Sure Guide to Builders (1729), The Young Builder's Rudiments (1730 and 1734), Ancient Masonry (1736), The City and Country Builder's and Workman's Treasury of Designs (1740 and later editions), The Builder's Jewel (1741). Architects, designers, cabinet makers, stonemasons, and craftsmen published pattern books and style guides to advertise their ideas, thereby hoping to attract a lucrative clientele.

The work of the Adam brothers set the style for domestic architecture and interiors for much of the latter half of the 18th century.

Robert and James Adam travelled in Italy and Dalmatia in the 1750s, observing the ruins of the classical world. On their return to Britain, they set themselves up with their older brother, John, as architects. Robert and James published a book entitled The Works in Architecture in instalments between 1773 and 1779. This book of engraved designs made the Adam repertory available throughout Europe. The Adam brothers aimed to simplify the rococo and baroque styles which had been fashionable in the preceding decades, to bring what they felt to be a lighter and more elegant feel to Georgian houses. The Works in Architecture illustrated the main buildings the Adam brothers had worked on and crucially documented the interiors, furniture and fittings, designed by the Adams. A parallel development of this phase of neoclassical design is the French Louis XVI style.

The Adam style moved away from the strict mathematical proportions previously found in Georgian rooms, and introduced curved walls and domes, decorated with elaborate plasterwork and striking mixed colour schemes using newly affordable paints in pea green, sky blue, lemon, lilac, bright pink, and red-brown terracotta.