Cley next the Sea, Anglo-Saxon Clæg "clay", is a village (population 376) on the River Glaven in Norfolk, England, north-west of Holt and east of Blakeney. The main A149 coast road runs through the centre of the village, causing congestion in the summer months due to the tight, narrow streets. It lies within the Norfolk Coast AONB (Area of Outstanding Natural Beauty) and the North Norfolk Heritage Coast.
The Grade I listed medieval church of St Margaret's, Cley is the largest church in the Blakeney Haven area. A ruined building on the marshes is known as Blakeney Chapel; despite its name, it is in Cley parish, and probably never had a religious purpose.