Mary Stewart Macklin CBE (born 20 October 1965)[2] is a Scottish businesswoman, entrepreneur and property developer, who is founder and executive chair of The HALO Urban Regeneration.

Macklin had entered into negotiations with supermarket chain Morrisons to expand into Scotland, using Kilmarnock as their debut store in 2004.

Under Macklin's ownership and direction, the KLIN Group would be responsible for the redevelopment of other major sites within Kilmarnock, including the restoration of Barclay House, the former offices and workspace for Andrew Barclay Sons & Co., turning the derelict building into commercial use and housing.

Following the announcement in 2009 by drinks company Diageo of their intention to close the Johnnie Walker bottling plant and production factory at Hill Street in Kilmarnock, Macklin joined a large protest of 20,000 people through the streets of Kilmarnock in an attempt to persuade Diageo to reverse their decisions.

Macklin speaks highly of her upbringing in Kilmarnock and as a reason for her work towards regeneration projects in the town.

[14] In the 2015 New Year Honours, Macklin was awarded with a Commander of the British Empire (CBE) for services to Economic Regeneration and Entrepreneurship in Scotland (Kilmarnock, Ayrshire and Arran).