Hydrogeology is the branch of geology which is concerned with the study of groundwater, its geological context, and geological concerns in the extraction of water from the earth.

Some areas of study within hydrogeology are:

Hyrdrogeology is therefore inextricably linked with hydrology (the study of the water cycle on Earth), sedimentology (the study of sedimentary rocks, and depositional environments), environmental science, physics, chemistry, and engineering.