An interstate compact is an agreement between two or more states of the United States of America. The United States Constitution provides that states may not enter into such agreements without the consent of Congress. Frequently, these agreements create a new governmental agency which is responsible for administering or improving some shared resource such as a seaport or public transportation infrastructure. In some cases, a compact serves simply as a coordination mechanism between independent authorities in the member states. The lists below reflect this distinction.

Operating interstate agencies

• Atlantic States Marine Fisheries Commission (Maine, New Hampshire, Massachusetts, Rhode Island, Connecticut, New York, New Jersey, Pennsylvania, Delaware, Maryland, Virginia, North Carolina, South Carolina, Georgia, and Florida)
• Bi-State Development Agency (Missouri and Illinois)
• Colorado River Compact (Colorado, New Mexico, Utah Wyoming, Nevada, Arizona, and California)
• Columbia River Gorge Commission (Oregon and Washington)
• Delaware River Port Authority (Pennsylvania and New Jersey)
• Delaware River Joint Toll Bridge Commission (Pennsylvania and New Jersey)
• Delaware River and Bay Authority (Delaware and New Jersey)
• Driver License Compact (all States except Georgia, Massachusetts, Michigan, Tennessee, and Wisconsin)
• Emergency Management Assistance Compact (as of 2005 all but California and Hawaii, plus Washington, D.C., Puerto Rico, and the U.S. Virgin Islands)
• Great Lakes Commission (Illinois, Indiana, Michigan, Minnesota, New York, Ohio, Pennsylvania, and Wisconsin)
• Gulf States Marine Fisheries Commission (Alabama, Florida, Louisiana, Mississippi, and Texas)
• Pacific States Marine Fisheries Commission (California, Oregon, Washington, Idaho, and Alaska)
• Port Authority of New York and New Jersey (New Jersey and New York)
• Washington Metropolitan Area Transportation Authority (Maryland, Virginia, and Washington, D.C.)
• Tahoe Regional Planning Agency ^* (California and Nevada)

Non-operating interstate compacts

• Northeast Dairy Compact (formerly set fluid milk prices for the New England states)

United States Constitution | United States interstate compacts