The F-84 Thunderjet was the first jet aircraft produced by Republic and first flew in Feb. 1946. The fuselage was an evolution of the company's P-47 Thunderbolt propeller-driven fighter, and the aircraft had straight wings. The F-84G was produced beginning in 1951 and was used during the Korean War, primarily for attacking North Korean ground targets.

Republic Co. is famous for the company producing the fighting bombers armed with sturdy such as P-47 Thunderbolt in WWII and F-105 Thunderchief in Vietnam war. F-84 Thunderjet is the first practical jet developed and produced by Republic Co. Its style had the image from the former reciprocating engine aircraft on the straight wings. The exhaust system was the center engine layout which took the air from the nose of the aircraft. It was emitted a jet of liquid fuel with the air from the air intake through the engine placed in the center of the fuselage.

The first trial aircraft of F-84 succeeded in the maiden flight in Feb. 1946, then the second prototype established the new record max speed as an American aircraft, 978km/h in Sep. 1946. Then C and D types modified on the engine and fuselage, and E type modified on extending the fuselage and adding an extra fuel tank were produced after the first mass-produced type, B type as the military dispositions was produced in Nov. 1947. Finally G type which had the straight wing was produced in 1951. The features of G type were an air-refuel system, the nuclear weapon load system which could load up to 2 tons, Allison J35A-29 engine, a big fuel tank and the extra fuel tank placed on the end of its wings. Therefore the cruising range reached more than 3600km. In 1952, G type was introduced into Korean conflict and had a hard dog fight with the new and powerful jet, Mig.

However G type played an important role ground attacking because of its special features such as the long cruising range.