Offshore drilling typically refers to the discovery and development of oil and gas resources which lie underwater. Most commonly, the term is used to describe oil extraction off the coasts of continents, though the term can also apply to drilling in lakes and inland seas.

Offshore drilling presents environmental challenges, especially in the Arctic or close to the shore. Controversies include the ongoing US offshore drilling debate.

There are many different types of platforms for offshore drilling activities, from shallow-water steel jackets and jackup barges, to floating Semi-submersibles and drillships able to operate in very deep waters.