When most of Queens County was still farmland, the elevated companies from Brooklyn and Manhattan extended their lines into Queens to a terminal at present-day 103 Street in Corona. Young Salvatore Fornatora saw the need for transportation beyond that terminal into central Flushing, and with a permit in hand from the New York City Department of Plant and Structures, began a operating bus line in 1919 from Corona to Flushing. When the elevated train was itself later extended into Flushing, Fornatora's bus service was relocated to Astoria. In the late 1920s, the company, which had by then acquired the name Woodside-Astoria Transportation Company, was operating several routes in Astoria, Woodside, and Maspeth.

In 1931, the company was incorporated with its present name, Triboro Coach Corporation. Over the succeeding years, Triboro expanded its operations throughout northwestern Queens County. By the middle of the decade, the City of New York was set to implement its plan to franchise buses throughout Queens County in each of four geographic zones. It was easy for the City to select a franchisee for zone A in northwestern Queens because Triboro had become a well respected pioneer company, already operated the largest number of routes, operated the most reliable buses, and was in the best financial condition. As a result of the franchise award in 1936, the number of routes operated by Triboro once again expanded with the takeover of some routes from other companies that had operated in the zone: route Q23 from North Shore Bus Company, route Q29 from Kings Coach Company, route Q33 from Municipal Motorbus Company, route Q38 from Affiliated Bus Transit Corporation, and route Q39 from National City Bus Lines. The years following saw the revision and refinement of routes to serve the expanding population of the borough, and the new municipal airport at North Beach (now known at LaGuardia Airport).

With costs increasing in the post-war period, Triboro experienced financial difficulties. In 1946, the Mayor offered the Triboro Coach franchise to Green Bus Lines if the company could act quickly to rescue the company from financial failure, and shortly thereafter, the company was in fact acquired by the stockholders of Green Bus Lines.

For many years, the Long Island Rail Road had operated trains between Manhattan and the Rockaways via a trestle across Jamaica Bay. The railroad discontinued operations to the Rockaways after a fire destroyed the trestle in 1950. To fill part of this transportation void, Triboro initiated service in 1956 between Woodside and Rockaway Park as a premium fare express service.

The last major expansion of local service occurred in 1961 when Triboro Coach purchased the B72 Junction Boulevard route from the New York City Transit Authority (the route number was changed to Q72). The route had been converted from streetcars to buses in 1949, and this route is the only route operated by Triboro Coach that is the direct successor of a streetcar route.

By the 1970s, deferred maintenance had taken its toll on the City's rapid transit system, and additional demands were being made for express bus services between Queens and Manhattan. In response to these requests, Triboro Coach initiated service on three express routes from central Queens County. hi 1988, Triboro began operation of its remaining two express routes.

In the mid 1970s, operating costs had increased dramatically, yet farebox revenues remained flat or even declined. While these events had many causes, some were the result of government policies favoring private automobile travel, dispersed land-use, suburbanization, and regulators' reluctance to increase fares. In New York City, a local public policy decision was made to subsidize the fare paid by passengers so that the fares would remain at a reasonable level, and to supply Triboro Coach and other companies with sufficient funding to continue operating these vital transportation services.

Today, Triboro Coach continues to operate the local and express routes in Queens County that were first franchised to the company in 1936, and later added to with the acquisition of the B72 and the implementation of new express service. The company operates out of a facility in Jackson Heights 24 hours per day. The bus fleet consists of 254 buses (of which 210  buses are in service each day at rush hour), with an average age of 8.5 years; approximately 89 percent of the bus fleet is wheelchair accessible. The City of New York funds the buses and service operated by Triboro Coach. Service is administered through a contract with the City of New York.

Local routes:

Q18, Q19, Q19A, Q19B, Q23, Q29, Q33, Q38, Q39, Q45, Q47, Q72

Limited-stop route:

Q53

Express routes:

QM10, QM11, QM12, QM22, QM24, QM24W