William Leiper FRIBA RSA (1839–1916) was a Scottish architect known particularly for his domestic architecture in and around the town of Helensburgh. In addition, he produced a small amount of fine ecclesiastical and commercial architecture in Glasgow and the Scottish Lowlands. He was also an accomplished watercolour artist, and from the late 1870s spent much spare time painting in oils and watercolours.

Helensburgh is a coastal town on the north side of the Firth of Clyde in Scotland, situated at the mouth of the Gareloch. Historically in Dunbartonshire, it became part of Argyll and Bute council area following local government reorganisation in 1996.