Glen Spey Distillery is a single malt Scottish whisky distillery located in Rothes, Moray, in the heart of the Speyside whisky region of Scotland. The Glen Spey distillery was constructed in 1878 by James Stewart & co. under the name Millhaugh as an extension to the  ‘Mill of Rothes'. In fact, the distillery started as an oatmeal factory. Initially, James Stewart was a corn merchant before entering the distilling business And renaming the distillery Glen Spey. In less than 10 years, James Stewart purchased Macallan Distillery and sells Glen Spey to W. & A. Gilbey for 11,000 GBP. They were a pioneering English company to have purchased a Scottish malt whisky distillery.

In 1920 the distillery was destroyed by fire and most of it had to be reconstructed. In 1962, W&A Gilbey integrated with United Wine Trader to form International Distillers and Vintners (IDV). In 1970, the Glen Spey distillery was totally refurbished and equipped with the latest technology. In addition, the distillery increased its number of stills from two to four, i.e., two wash stills and two spirit stills, each equipped with a purifier. They act like small condensers, returning some of the alcohol that has already evaporated into the still for further distillation.

Glenn Spey only produced a handful of official bottles throughout its lifetime, but the first official bottles were not released until 2010. Currently, the only official bottling released is a 21-year-old.

The 12 year old ‘Flora & Fauna’ series was launched in 2001 and has been used by collectors as a substitute for official bottling.

The capacity of Glen Spey distillery is relatively small, its annual production is about 1.4 million litres. Glen Spey draws its water from the Doonie burn (stream), which is very close to the distillery. This water source has been a controversial issue in the past as it is shared by several other close by distilleries that not only draw water from the spring but also discard their hot water that had been used to cool their pot stills into it.

Currently, the malt used to make Glen Spey whisky comes from one of Diageo's industrial units. The distillery utilized its own maltings until 1969-70 when the site went through a large reconstruction. The maltings used by the distillery are unpeated.

Glen Spey is also known to be the only Rothes distillery to boast of a ghost. The history of the ghost dates back to World War II, when a soldier working at the distillery was fatally electrified in an accident. It was reported that the spirit of the ghost still roams the distillery at night.

In the late twentieth century, Glen Spey experienced a series of mergers that eventually resulted in Diageo acquiring the distillery.