James Stewart converted his meal mill, Millhaugh into Glen Spey Distillery in 1884 to add to his production of Macallan. Glen Spey is situated across the burn from Glen Rothes, Stewart sparked off an argument into who owned the water rights. In 1887 a London-based drinks company, W&A Gilbey, bought the distillery, they also bought Strathmill and Knockando Distilleries. Later they acquired Aberdeen based blending company James Catto, from the help of James Catto they began exporting whisky.
In 1962 W&A Gilbey?s merged with United Wine Traders Limited to form IDV. In 1970 the distillery was refurbished and extended to house two new stills. By 1997 several more mergers had occurred and the distillery was owned by UDV, now known as Diageo.