The United States Coast Guard (USCG) is a branch of the United States Armed Forces and one of seven uniformed services. It is unique among the military branches in that it has a maritime law enforcement mission (with jurisdiction both domestically and in international waters) and a federal regulatory agency mission as part of its mission set. It operates under the Department of Homeland Security during peacetime, and can be transferred to the Department of the Navy by the President or Congress during a time of war.

The overall mission of the Coast Guard is to protect the public, the environment, and the United States economic and security interests in any maritime region in which those interests may be at risk, including international waters and United States coasts, ports, and inland waterways.

The Coast Guard motto is "Semper Paratus", Latin for "Always Ready" or "Always Prepared".