Pladda (Scottish Gaelic: Pladaigh) is an uninhabited island 1 km off the south coast of the Isle of Arran in the Firth of Clyde at grid reference NS027191, western Scotland. It is home to the automated Pladda Lighthouse. The island is privately owned, having been put up for sale by Arran Estate in 1990.
Pladda is a small, flat, teardrop-shaped island, less than a kilometre along its length and rising to just 27 metres (89 ft) above sea level. Unusual for such a small island it has its own source of fresh water.
Pladda shares its name with Pladda Island, a tiny islet situated in the Lynn of Lorn between Lismore and Ardmucknish Bay.
Pladda Lighthouse and its ancillary buildings stand at the southern end of Pladda.
There appears to have been a church or chapel on Pladda. John of Fordun and other chroniclers from 1400 to 1500 speak of the isle of St Blase of Pladda.
Nothing now remains to mark its site, and its whereabouts are unknown.
Coordinates: 55°25′33″N 5°07′10″W / 55.42596°N 5.11945°W