Alder and Mackay Limited was a manufacturer of gas meters based in Edinburgh and Bradford. In 1914 the business had 450 employees. The company was amongst the exhibitors at the 1937 British Industries Fair, describing its products as 'Latest designs Ordinary and Prepayment Dry Gas Meters. Demonstration and Test Meters. Standard Test Holder and Meter Testing Apparatus.'

The company is known to have been active until at least 1962, by which time it was a subsidiary of United Gas Industries.