Hill House in Helensburgh, Scotland is a building by architects and designers Charles and Margaret Macdonald Mackintosh. The house is a prominent example of the Modern Style (British Art Nouveau style). It was designed and built for the publisher Walter Blackie in 1902–1904. Mackintosh also designed the house interior, including furniture and fittings. In 1982, the house was donated to the National Trust for Scotland (NTS) which maintains and opens the house to visitors.