Commercial operations began at Williamtown in 1947 when the federal government opened the existing Royal Australian Air Force (RAAF) airport to civil aviation. The airport remained under government control until 1990 when responsibility for its operation was handed over to Newcastle City Council and Port Stephens Council. The current operator, Newcastle Airport Pty Ltd, was formed by the two councils in 1993.

Scheduled services to the airport commenced in February 1948, with Trans Australia Airlines using Douglas DC-3 aircraft to service a Sydney–Newcastle–Brisbane route. A new passenger terminal was constructed in 1975. During the 1970s, Masling Airlines operated Cessna 402 aircraft on commuter flights between Newcastle and Sydney, and in 1980 with the acquisition of larger Embraer EMB 110 Bandeirante aircraft added a Newcastle – Canberra route. Passenger numbers increased during the 1980s with new airlines and routes serving the airport, including jet services utilising Fokker F28s of Air New South Wales and Ansett Boeing 737s.

Impulse Airlines established a base at the airport in the early 1990s, creating a maintenance facility. In 1994, Impulse added the first direct Newcastle – Melbourne flights to their network utilising British Aerospace Jetstream 41 aircraft. In 1996, owing largely Impulse's establishment of Newcastle as a regional hub, the terminal facilities were upgraded to handle growing passenger volumes. In 2000, Impulse acquired Boeing 717s and rebranded itself as a low-cost carrier. Newcastle Airport remained an integral part of the Impulse route network until the company was bought out by Qantas the following year. Following Qantas' acquisition of Impulse in 2001, the airport became the maintenance base for Jetstar's Airbus A320 fleet. The base also provides third party aircraft maintenance for the QantasLink's Boeing 717s.

In 1997, BAE Systems was awarded the contract for assembly and ongoing system support for the Hawk 127 Lead in Fighters for the RAAF. As part of the contract, a large facility was built adjacent to the passenger terminal at a cost of $15 million. Twenty-one of the thirty three aircraft were assembled at Williamtown, with the final deliveries taking place in October 2001. The BAE facility forms part of the Williamtown Aerospace Centre precinct.

In November 2006, a $8.25 million upgrade to the terminal facilities was completed. This development doubled the available floor space in the terminal building, enhanced security screening and added a third departure gate, two baggage carousels and a retail concourse with five stores. In the same year, Jetstar Engineering invested $29 million towards improvements to the former Impulse maintenance facilities to allow heavy maintenance on A320 family aircraft to be conducted at the airport, Aeropelican Air Services moved operations to Williamtown from Belmont Airport and Newcastle Airport was named Regional Airport of the Year by the Australian airports industry. Additional car parking and enhanced set down and pick up landside access was added in 2006 at a further cost of $2.7 million.

On 24 February 2015, Newcastle Airport's a 2,600 m2 (27,986 sq ft) extension was opened. The new expansion opened the airport to possible international services with a dedicated area for permanent customs, immigration and quarantine facilities. This expansion was the first stage of an $80 million redevelopment, with the existing terminal undergoing a full refurbishment. Redevelopment works for the adjacent RAAF base Williamtown, including a 650 m (2,133 ft) extension of the shared runway, began in January 2015.