This is a list of seas of the World Ocean, including marginal seas, areas of water, various gulfs, bights, bays, and straits. In many cases it is a matter of tradition for a body of water to be named a sea or a bay, etc., therefore all these types are listed here.

Terminology

There are several terms used for bulges of ocean that result from indentations of land, which overlap in definition, and which are not consistently differentiated: Many features could be considered to be more than one of these, and all of these terms are used in place names inconsistently; especially bays, gulfs, and bights, which can be very large or very small. This list includes large areas of water no matter the term used in the name.

Largest seas by area

The largest terrestrial seas, in decreasing order of area, are:

Marginal seas by ocean

Seas may be considered marginal between ocean and land, or between oceans in which case they may be treated as marginal parts of either. There is no single ultimate authority on the matter.

Arctic Ocean

(clockwise from 180°)

Atlantic Ocean

In addition to the marginal seas listed in the three subsections below, the Arctic Ocean itself is sometimes also considered a marginal sea of the Atlantic.

Africa and Eurasia

Americas

(coast-wise from north to south)

Northern islands

(from east to west)

Indian Ocean

Pacific Ocean

Americas

Australia and Eurasia

Southern Ocean

Defined by ocean currents

While all other seas in the world are defined at least in part by land boundaries, there is only one sea which is defined only by ocean currents:

Not included

Entities called "seas" which are not divisions of the World Ocean are not included in this list. Excluded are: