Siddington is a civil parish in the unitary authority of Cheshire East and the ceremonial county of Cheshire, England. It consists of farms; a picnic site; Redesmere, a half-mile long lake; and the Capesthorne Estate. The village is located at the crossroads of the A34 with the B5392 approximately half-way between Alderley Edge and Congleton.
Redesmere, created as a feeder reservoir for the ornamental lakes of Capesthorne Hall in the late 18th century, once had an island. According to popular belief the island floated, and it is marked as such on the 1842 One Inch Ordnance Survey map, though the 1975 1:25000 Ordnance Survey map shows that it had become joined with the bank by then. Local legend says that it came into being as a result of a vow by a knight who believed his lady was unfaithful, and that he would not look on her face again until the island floated. Soon after he fell ill, but she remained loyal to him and nursed him back to health. There then followed a storm which tore the island from the bottom of the lake, and it floated ever since, clearing the lady's name.
The writer Alan Garner included a reference to the Floating Island of Redesmere in his novel The Weirdstone of Brisingamen.