John McLachlan (6 June 1843 – 13 May 1893) was a Scottish architect, based in Edinburgh operating in the late 19th century.
In 1868 he started his own practice and by 1878 had prestigious offices at York Buildings in the New Town.
Later, he formed a business association with Thomas P. Marwick and his architectural style changed from Victorian Baronial to Queen Anne Revival.
He died very young, aged only 49, at home at 33 Queens Crescent, and was buried in Morningside Cemetery, Edinburgh, near the southern edge.
The grave lies back-to-back with Robert Morham and Margaret's parents.