Known as Sunset Field before 1941, it was purchased from the county by the War Department and renamed Geiger Field (hence the IATA code GEG) after Major Harold Geiger, an Army aviation pioneer who died in a crash in 1927.

During World War II, Geiger Field was a major training base by Second Air Force as a group training airfield for B-17 Flying Fortress heavy bombardment units, with new aircraft being obtained from Boeing near Seattle. It was also used by Air Technical Service Command as an aircraft maintenance and supply depot; Deer Park Airport and Felts Field were auxiliaries.

In 1943, General Hap Arnold established the first formal fire protection training course at Geiger Field, Washington. It was used until 1946.

Geiger Field was served by a rail connection to the Great Northern Railway.

Geiger was closed in late 1945 and turned over to War Assets Administration (WAA), then transferred to Spokane County and developed into a commercial airport. The airport hosted USAF Air Defense Command interceptor units during the Cold War for air defense of Hanford Nuclear Reservation and Grand Coulee Dam. Built in 1942 as the Spokane Air Depot, Fairchild Air Force Base is four miles (6 km) to the west.

It became Spokane's municipal airport in 1946, replacing Felts Field, and received its present name in 1960, after the City of Spokane was allotted Spokane Geiger Field by the Surplus Property Act and Air Canada started service to Calgary. In November 1972, the 4702d Defense Wing moved to the airfield. It was still used by the Air Force into the early 1960s, with the 84th Fighter Group operating Convair F-106 Delta Dart interceptors. The airport code is still GEG, for Geiger Field.

The current Concourse A and B complex opened in 1965, designed by Warren C. Heylman and William Trogdon.

Expansion from the 1970s

A second level was added to Concourse A and Concourse B in 1974.

The airport has a Master Plan, which includes a third runway and gates added to Concourse C.

A new control tower has been built south of the airport, replacing the one near Concourse C. The new control tower is the tallest one in the State. The Terminal, Rotunda, and Concourse C Enhancement Project (TRACE) was recently completed, designed by Bernardo/Wills Architects, P.C. The project, which concluded in November 2006, added retail space and expanded security checkpoints in the airport's three concourses, and gave the Rotunda an aesthetic renovation. In 2010, 2000 feet was added to Runway 3–21 and parallel taxiways 'A' and 'G', enabling heavier aircraft departures in summer months.

By 2023, the airport plans to add new gates, centralized security and expanded baggage claim space as it looks to add more direct flights, including to the east coast, to capitalize on and accommodate growing passenger and cargo traffic; the Spokane market has been hosting big events and attracting business to the area.

Terminal renovation and expansion (TREX) program

On October 20, 2022, the airport broke ground on the first phase of the project which includes expansion of Concourse C. The $150 million addition will add 144,000 square feet, 6 new gates and modernization of the existing terminal. The first portion of the expanded concourse, which includes three gates at the west end, opened in June 2024. The remainder of the project is planned to begin construction in late 2024 and be completed the following year.

The second phase of the TREX program is focused on creating a centralized TSA screening checkpoint and baggage claim, as well as an improved operations center. This central connection will also allow easier navigation between the A/B and C concourses. As of January 2023, the 145,000 square foot Central Hall is estimated to cost $179 million and has a planned construction timeline of 2025 to 2027. Other projects planned in the TREX program include relocation of the rental car facilities, and renovation of the A/B concourse.

The airport received $6.5 million from the 2021 Bipartisan Infrastructure Law to help fund the project.