Millisle Old Mill, Mill Road, Ballycopeland, Millisle, Newtownards, Co. Down, BT22 2EA

Millisle Old Mill is a three-storey disused corn mill of mid-eighteenth century origin, situated on the south side of Mill Road at the north-west corner of Millisle village, overlooking the mill race on sloping ground.

The mill is constructed of rubble with a roughly square plan and double gables. Sections of the walls retain rough cast render, though much of the southern elevation is covered in ivy. Most of the former window and door openings are now blocked, with the exception of a timber-sheeted door on the northern facade, accessed by three stone steps. The gabled roof of the northern section retains most of its Bangor blue slates, but the southern roof section has partly collapsed. The building is substantially intact but no longer contains any machinery, and both the water wheel and external machinery have been removed.

The mill probably dates from the mid-eighteenth century and was originally owned by the Crommelin family. In May 1757 it was advertised in the Belfast News-Letter as being "well slated and in good repair". In 1790 Robert Carmichael leased the mill from Delacherois Crommelin for a term of three lives and forty-one years at an annual rent of £170 sterling. Around 1801, Robert Carmichael built an auxiliary windmill a short distance to the west.

Around 1860, Robert's brothers David and William Carmichael constructed a steam-driven flax mill to the south of the mill race and substantially renovated the corn mill at the same time. In March 1861 the steam engine in the flax mill exploded, killing four men. The Carmichaels sold their milling interests in Millisle around 1889 to James Fulton. Upon Fulton's death in 1906, the mills passed to his brother-in-law James Mitchell, whose family operated the corn mill until the 1950s. The building has remained largely derelict since then.

The remains of the flax mill survive to the south of the mill race, though little of this structure has endured; what remains is now incorporated into a modern structure with a curved corrugated iron roof.