Strathclyde Grain Whisky Distillery was built in 1927 by the historic London gin company Seager Evans (founded in 1805) to ensure a stable supply of distilled spirits. The distillery is located on the south bank of the River Clyde in Glasgow, drawing water from Loch Katrine in the Trossachs. In 1936, Seager Evans' Scotch whisky production was significantly enhanced through the acquisition of wine and spirits merchant W.H. Chaplin & Company. Chaplin & Company had acquired the famous brand Long John in 1911 from Long John Macdonald, successor of Ben Nevis Distillery. In 1937, Seager Evans purchased Glenugie Distillery in Peterhead. In 1956, Seager Evans was acquired by Schenley Industries Inc., an American distiller from New York State, at a time when blended Scotch whisky was rising worldwide—an investment that was undoubtedly welcome. Ownership of the Scottish distilleries was transferred to Strathclyde & Long John Distilleries Ltd, which was soon simplified to Long John Distilleries Ltd, and renamed Long John International Ltd after 1970. In 1975, it was sold to Whitbread & Company Ltd, whose distilling interests were sold to Allied Lyons in 1990 for £454 million. Strathclyde was rebuilt between 1973 and 1978, installing two continuous stills for grain whisky production and five continuous stills for neutral spirit production. After the closure of Dumbarton Distillery in 2002, Allied spent over £7 million to increase Strathclyde's capacity from 32 million litres of pure alcohol per annum to 40 million litres. Following Allied's dissolution in 2005, Strathclyde was transferred to Chivas Brothers.

Between 1956-1957, a rare 'distillery within a distillery' was born when Kinclaith malt distillery was constructed inside the Strathclyde grain distillery complex to supply spirit for the Long John blend. Just two decades later, after Whitbread's acquisition of Long John International, Kinclaith was dismantled in 1976-1977 to accommodate Strathclyde's expansion, leaving behind only a handful of extremely rare bottlings.