The geology of the United Kingdom is the geology of Great Britain and Northern Ireland. This includes rocks of almost all geological periods. The United Kingdom's oldest rocks were formed during the Archaean Eon of the Earth's geological history. Its youngest sedimentary deposits formed during the Quaternary period.

Geological map of Great Britain
	Quaternary (Alluvium)
	Paleogene / Neogene (Tertiary)
	Cretaceous
	Lower Cretaceous
	middle/upper Jurassic
	lower Jurassic
	upper Triassic
	lower Triassic
	upper Permian
	lower Permian
	upper Carboniferous (Coal Measures)
	middle Carboniferous
	lower Carboniferous (limestone)
	Devonian
	Ordovician / Silurian
	Cambrian
	Neoproterozoic
	Proterozoic (upper Precambrian)
	Lewisian (lower Precambrian)
	granite
	Paleogene volcanics