Biggar Castle may have been a 12th or 13th century castle which had been demolished by the 17th century. Nothing of it now remains.
Little seems to be written about Biggar Castle, but the main sources appear to be the Ordnance Survey Name Book, the “Official Guide to Biggar” by Gilbert Rae, and the book “Biggar and the House of Fleming”.
Biggar Castle is said to have been built in the 12th century, however this would make it contemporary with the motte and bailey castle at Gillespie Moat to the south-west.
In “The Castles of Scotland”, Martin Coventry includes a brief entry for Biggar Castle simply stating that it was a 13th century castle of the Flemings.
Mike Salter, writing in “The Castles of South-West Scotland”, refers briefly to Biggar Castle belonging to the Fleming family from the 12th century before they moved to Boghall Castle in the 14th century.
Having two castles so close together in Biggar at the same time seems unlikely, so perhaps some of the sources have confused the two sites.
It perhaps seems more likely that Biggar Castle was built later, perhaps in the 13th or 14th century, after the motte and bailey castle was abandoned.
Not much else seems to be known about the castle. It would appear to have been replaced by a house which was known as the Tower, Fortalice, or Tower House, and which was bequeathed by James Brown, a grocer, to the Reverend Alexander Livingstone in 1659.
The church ran a school in what was then known as “James Brown’s tower”, and a carved lintel survives from around this time. Carved with the words “Ora et labora ut floreant studia – 1691” – “Pray and work to flourish study” – it is said to be installed above a door in the north-east wall of the current building, although I couldn’t find it.
In 1774 the church sold the house to Richard Johnston and his wife Agnes Muir, also known as Nannie Muir, who ran it as a lodging house. The site was apparently later occupied by a slaughter house. The building on the site now is seemingly 19th century in date, and currently run as a shop.