To meet a French armed services requirement for a medium transport helicopter, Sud-Aviation flew the prototype SE.3200 Frelon (hornet) on 10 June 1959. Powered by three Turmo IIIB turboshafts, the SE.3200 had large external fuel tanks that left the interior clear for a maximum of 28 troops, and a swing-tail fuselage to simplify cargo loading. However, development was terminated in favour of a larger and more capable helicopter designed in conjunction with Sikorsky and Fiat. What was to become Western Europe's largest production helicopter emerged with a rotor system of Sikorsky design, and with a watertight hull suitable for amphibious operation. Two military prototypes of the Super Frelon were built, the SA 3210-01 troop transport, and the SA 3210-02 maritime version for the Aeronavale on 28 May 1963.
Four pre-production aircraft were built under the new designation SA 321 Super Frelon. These were followed in October 1965 by production SA 321G anti-submarine warfare helicopters for the Aeronavale. Apart from ship-based ASW missions, the SA 321G also carried out sanitisation patrols in support of Redoutable class ballistic missile submarines. Some were modified with nose-mounted targeting radar for Exocet anti-ship missiles. Five SA 321GA freighters, originally used in support of the Pacific nuclear test centre, were transferred to assault support duties. In 2003, the surviving Aeronavale Super Frelons are assigned to transport duties including commando transport, VertRep and SAR.
Six radar-equipped SA 321GM helicopters were delivered to Libya in 1980-81. The SA 321G was also modified for air force and army service. Designated SA 321H, a total of 16 was delivered from 1977 to the Iraqi air force with radar and Exocets. These aircraft were used in the Iran-Iraq conflict and the 1991 Gulf War, in which at least one example was destroyed.
The SA 321JA was a higher weight version of the commercial SA 321J, of which the People's Republic of China navy received 16 aircraft fitted with targeting radar. Non-amphibious military export versions included 12 SA 321K transports for Israel, 16 similar SA 321L transports for South Africa and eight SA 321M SAR/transports for Libya.
When French production ended in 1983 a total of 99 Super Frelons had been built, but production continued in China under license-agreement as the Changhe Z-8. Eight Israeli aircraft were re-engined with T58 engines and later sold to Argentina.