The distillery was founded by John Duff along with Charles Shirres and George Thomson in 1893. John Duff had been associated with several other distilleries and projects elsewhere. The land was leased from Longmorn Farm and Duff was in charge of the construction and fitting out of the new distillery.

Longmorn used water from local springs and bought its barley from farms nearby in the fertile Laich of Moray. The Mannoch Hill near the site was an ample source of peat for the kilns. The motive power for the distillery was provided entirely by its large water wheel. The modern distillery had its own floor maltings and a workable steam engine. The Great North of Scotland Railway Company’s Longmorn Station was connected by a branch line and sidings. This made it convenient for the delivery of barley, coal and other materials to the distillery and for the shipment of whisky to customers.

The Longmorn Grants controlled the distillery till 1970, when the company joined with The Glenlivet and Glen Grant Distilleries Ltd and Hill, Thomson & Co Ltd to form The Glenlivet Distillers Ltd. The new company pumped in more money and life into Longmorn Distillery. It was expanded in 1972 to add two stills. Two more were added in 1974, as the demand for Longmorn whisky as the ‘top dressing’ in many of Scotland’s best blended whiskies grew.

The distillery produces a single malt Scotch whisky with a mellow and complex character, which is known as Speyside’s best kept secret. Though it is not easily available it has become very popular with connoisseurs of single malts. It is prized by blenders as highly as the whisky of its sister distilleries, Glenlivet and Glen Grant. In 1994 a fifteen year old Longmorn with a new bottle and packaging was launched. In 1978 The Glenlivet Distillers Ltd became Chivas Brothers, one of the Seagram family of companies. In 2001 Chivas Brothers were acquired by the Pernod Ricard Group.