The American Council of Engineering Companies (ACEC) represents America's engineering industry. Council members – numbering more than 5,500 firms throughout the country – are engaged in a wide range of engineering works that propel the nation's economy, and enhance and safeguard America's quality of life. These works allow Americans to drink clean water, enjoy a healthy life, take advantage of new technologies, and travel safely and efficiently. The Council's mission is to contribute to America's prosperity and welfare by advancing the business interests of member firms.

ACEC's roots date back to 1905 when eight engineers in private practice established the Association of Architectural Engineers, the forerunner of ACEC, to promote their business interests and contributions to the nation's growth. Today ACEC is a large federation of 51 state and regional councils representing the great breadth of America's engineering industry. ACEC member firms employ more than 300,000 engineers, architects, land surveyors, scientists, and other specialists, responsible for more than $100 billion of private and public works annually. Member firms range in size from a single registered professional engineer to corporations employing thousands of professionals.

ACEC California is ACEC's largest member organization.