W & M Duncan and Company, best known as "Duncan's of Edinburgh", was a Scottish confectioner. The company's most popular and enduring product was the Walnut Whip, which is now manufactured by Nestlé Rowntree's.
Mary Duncan, along with her son William, founded a cake business in Dundee in 1861. In 1884 the company moved to 205 High Street, Edinburgh, and began to manufacture chocolate confectionery. In 1896 it moved to the Regent Confectionery Works in Beaverhall Road, Edinburgh.
The Walnut Whip was launched in 1910.
The business was acquired by Rowntree Mackintosh in 1947. Rowntree closed the factory in 1987 but it was reopened immediately by new owners trading as "Duncans of Scotland". Within ten years the new Duncans business moved to Bellshill, Lanarkshire, and passed through several owners before becoming part of J. E. Wilson & Sons (Kendal).