Military use

In the 1930s Santa Rosa had a small municipal airfield owned by Richfield Oil Corporation next to the Redwood Highway about 6 miles southeast of the present airport. Use of the 3,000-foot sod runway at the earlier airfield was discontinued during World War II as facilities at the present airport improved.

Opened in June 1942 and known as Santa Rosa Army Air Field, the airfield was assigned to Fourth Air Force as a group and replacement training airfield. Known units assigned to Santa Rosa were:

354th Fighter Group, March–June 1943

357th Fighter Group, June–August 1943

363d Fighter Group, August–October 1943

367th Fighter Group, October–December 1943

The 478th Fighter Group was permanently assigned to Santa Rosa in December 1943 and began training replacement pilots, who were sent to combat units overseas after graduation.

The airfield was inactivated on January 31, 1946 during winter and turned over to the War Assets Administration for eventual conversion to a civil airport.

Airline flights

From the late-1940s to the mid-1970s Southwest Airways and successors Pacific Air Lines, Air West and Hughes Airwest served Santa Rosa. Southwest Airways Douglas DC-3s followed by Pacific, Air West and Hughes Airwest Fairchild F-27 turboprops mainly flew to San Francisco (SFO). Pacific Air Lines had introduced F-27 aircraft on its Santa Rosa service by 1964 with these new propjets subsequently replacing the airline's Martin 4-0-4 piston-powered aircraft on all of its flights into the airport. In 1967 Pacific was operating daily F-27 service on a roundtrip routing of Portland, OR - Crescent City - Eureka/Arcata - Santa Rosa - San Francisco. By 1968, one of the Air West F-27 flights serving the airport was operating a daily southbound routing of Redding - Santa Rosa - Oakland - San Francisco. In the summer of 1972, Hughes Airwest was operating two nonstop F-27 flights every weekday to San Francisco. However, by 1975 Hughes Airwest was no longer serving Santa Rosa.

Commuter airlines flew STS to San Francisco (SFO) until 2001 as well as to San Jose (SJC) at various times. In 1969 Golden Pacific Airlines (1969–1973) was operating six roundtrip flights every weekday between the airport and SFO as well as direct flights to Eureka, Lake Tahoe, Reno, Stockton and Ukiah with Beechcraft 99 commuter turboprops During the mid and late 1970s Eureka Aero and successor Air Pacific (United States) operated de Havilland Canada DHC-6 Twin Otter service to Eureka, Oakland, Sacramento and San Francisco. In 1985 Westates Airlines Convair CV-580 turboprops flew nonstop to Los Angeles for several months before ceasing operations; their July 1985 timetable listed 38 round trips a week between STS and LAX. Other turboprop flights included American Eagle Fairchild Swearingen Metroliners operated by Wings West Airlines for American Airlines nonstop to SFO and San Jose (SJC). In late 1989 American Eagle had three Metros a day to SFO and four a day to SJC. In 1995 Reno Air Express was operating codeshare BAe Jetstream 31 nonstop service from Eureka/Arcata, Reno and San Jose flown by Mid Pacific Air on behalf of Reno Air.

On September 15, 1974, the airport's main taxi runway was dedicated to and named after local pilot and businessman Lloyd C. Hayes, making it one of the rare instances where a U.S. airport taxiway was officially named after an individual.

In the mid-1980s United Airlines entered into a code sharing agreement with WestAir, a commuter airline that had previously served STS with Cessna 402s and de Havilland Canada DHC-6 Twin Otters to San Francisco. WestAir then began flying as United Express to SFO until 2001. Westair operated its United Express service with Embraer EMB-110 Bandeirante, Short 360, BAe Jetstream 31 and Embraer EMB-120 Brasilia turboprops.

In 1989 jet service arrived in Santa Rosa when WestAir operating as United Express began flying four weekday BAe 146-200 nonstops to Los Angeles, soon replaced with Embraer EMB-120 Brasilia turboprops with this service to LAX then ending in 1991. The Westair BAe 146s were Santa Rosa's only jet flights until Allegiant Air jets appeared on May 19, 2016 followed by American Eagle on February 16, 2017. WestAir formerly operated as Stol Air Commuter flying Britten-Norman Islanders and Trislanders to San Francisco. Stol Air Commuter had administrative offices in Santa Rosa. In June 2001 United Express operated by SkyWest Airlines was the only airline serving Santa Rosa with six Embraer EMB-120 Brasilia flights a day into the airport including four daily nonstops from Los Angeles (LAX) and two flights a day from San Francisco (SFO). United Express then left Santa Rosa later in 2001 (and would not return until 2017) with the airport not having any scheduled passenger airline service for several years during the early and mid-2000s.

In March 2007 airline service resumed; Horizon Air, a subsidiary of Alaska Airlines, began flights to Seattle/Tacoma and Los Angeles operated with Bombardier Q400 propjets.