Fa'side Castle (Faside Estate) has previously been known as Fawside, Falside, Ffauside, Fauxside, or Fawsyde and is a 15th-century keep located in East Lothian in Scotland.

[1] The name dates from 1189, when the monks of Newbattle Abbey granted land to Saer de Quincy, 1st Earl of Winchester to build the castle on the site.

The land was lost to Robert the Bruce after the De Quincy family declared their loyalty to Edward I of England.

[1] A surviving oak bed, now at Biggar Museum, was made for Margaret Fawside, who married Patrick Levingstone of Saltcoats near Gullane.

[4] On 5 November 1620 a number of local and neighbouring landowners had dinner with Janet Lawson, Lady Fawside, at the castle and illegally combined together to set and raised the price of coals from their coalmines.

The Privy Council of Scotland found their actions unlawful and the lairds were ordered to pay a fine of £2,000 and be imprisoned in Edinburgh Castle.