Alyn and Deeside (Welsh: Alun a Glannau Dyfrdwy) was one of six local government districts in the county of Clwyd, north-east Wales from 1974 to 1996.

The neighbouring district was similarly called Delyn, combining the names of the same two rivers the other way around.

[2] The shadow council elected in 1973 requested that the name be changed from Alyn-Dee to Alyn and Deeside.

The change of name was confirmed by the Secretary of State for Wales on 19 October 1973, before the new district formally came into being.

In 2018, after Unilever's lease expired, Flintshire County Council brought the building back into civic use, renaming it "Ty Dewi Sant" and moving various departments there from County Hall, Mold.