USA 3000 Airlines was an American low-cost carrier based in Pittsburgh, Pennsylvania. It was founded in 1998 by entrepreneur and pilot, Michael L. Conway. The airline primarily operated flights from the United States to vacation destinations in the Caribbean, Mexico, and Central America.

The airline's first aircraft was a Boeing 757-200 with 174 seats, which it used for its inaugural flight on December 1, 1998. The airline primarily used this aircraft to serve its leisure destinations. In 2003, the airline added two Airbus A320-200 aircraft to its fleet. These aircraft were configured with 150 seats and were used to expand the airline's service to other destinations in the United States.

In 2004, USA 3000 Airlines was the first airline to be certified under the FAA's "Enhanced Security Program," which was designed to enhance security on airlines operating in the United States. The program required airlines to implement additional security measures, such as the use of secondary screening of passengers and baggage. The airline was also the first to be certified under the FAA's "Enhanced Airport Security Program," which required airports to implement additional security measures.

In 2006, USA 3000 Airlines was acquired by Apple Vacations, a travel company based in Pennsylvania. This marked the first time an airline had been acquired by another company. As part of the acquisition, Apple Vacations merged USA 3000 Airlines with its existing airline, Allegiant Air. The merger resulted in the new airline operating under the Allegiant Air name.

In 2010, USA 3000 Airlines was the first airline to be certified under the FAA's "Secure Flight Program." This program required airlines to collect passenger information before they are allowed to board a plane. This information is used to verify the identity of the passenger and to help prevent terrorist attacks against the United States.

In 2011, USA 3000 Airlines ceased operations. The airline had experienced a steady decline in passenger numbers due to the economic recession and the rise of low-cost carriers. The airline was also struggling to compete with its larger rivals, including Southwest Airlines and JetBlue Airways.

USA 3000 Airlines was a pioneer of the low-cost airline industry in the United States. The airline was the first to be certified under the FAA's "Enhanced Security Program" and the first to be certified under the FAA's "Secure Flight Program." The airline's legacy will live on in the form of Allegiant Air, which continues to operate flights to leisure destinations in the United States.